Section N ( 03/11/2010 )

ELECTRICAL EQUIPMENT

N.1     Lubrication and general maintenance
N.2     Battery maintenance
N.3     Dynamo lubrication and maintenance 
N.4     The control box
N.5     The fuse unit
N.6     The starter motor
N.7     Removing the starter from engine and dismantling
N.8     Ignition
N.9     The flashing lamp direction indicators
N10    Windscreen wiper
N11    Lighting
N12    Location and remedy of faults  

NX01 Wiper motor

 

Electrical System 
The electrical system consists of the 12-volt generator, starter motor, battery and ignition circuit. It also includes the circuits for the instruments and other electrically controlled accessories.

GENERAL AND DATA

All electrical equipment is of 'Lucas' make, designed for maximum service with minimum need for attention. 

Battery
12-volt. lead acid. 7-plate (tall). capacity 43 amp/hr. at 20 hr. rate. Type BT7A.
or 12-volt. 9-plate (wet). capacity 57 amp/hr. at 20 hr. rate. Type BT9A.
or 12-volt, 9-plate (dry), capacity 57 amp/hr. at 20 hr. rate. Type BT9A.

Dynamo :
C39PV-2. Model 22265.
Cut-in speed 1.050 - 1.200 r.p.m. at 13 generator volts.
Max. output 19 amps at 1.980-2.150 r.p.m. at 13,5 generator volts.
Field resistance 6-1 ohms.

Distributor
Type 1/2A4, contact breaker gap 0,012->0,015".

Ignition Control
Type LA 12 (45053); current consumption, running 1 amp, stall 2-7 amp.

Control Box
Type RB1O6-2.

Regulation Setting:
 10C (50 F)  16,1 16,7 volts
 20C (68F)   16,0 16,6 volts
 30C (86F)   15,9 16,5 volts
 40C (104F) 15,8 16,4 volts
 Cut-in voltage 12,7-13,3 volts, drop of voltage 9-10 volts;
reserve current 3-5 amp.

Starter Motor
Type M35G (25022). nominal voltage 12.
With armature locked. torque 7-7 lb/ft. current 330-350 amp. voltage 7,5-7,1 volts. With armature running at 1,000 r.p.m. torque 4-5 lb/ft current 215-235 amp, voltage 9,1-8,7 volts.
Light running test. 45 amp at 8.500-1.000 r.p.m.

Fuse Unit
Type 4FJ: fuses 35 amp.

Flasber Light Indicator
Flasber Unit Type FL5. flasber lights front and rear. 12 volt. 21-watt, Lucas 382.

Lighting
Headlamp, 60/45-watt. Lucas 7002; sidelamp, Lucas 207; taillight. 12-volt. 6/21 -watt. Lucas 380-. number plate lamp. 12-volt. 6-watt. Lucas 989. panel illumination, 12 volt, 2,2-watt. Lucas 987. warning lamps (ignition, oil pressure and main beam). 12-volt. 2-watt-, flasher lamps. Lucas 987.

  N1

LUBRICATION AND GENERAL MAINTENANCE

 Check contact breaker after first 500 miles. The contact breaker gap should be 0,015 inch when fully opened. Access to the contact breaker is gained by opening back the two side clips and lifting off the moulded cover. To check the setting, turn the engine slowly by hand until a position of maximum opening is reached, then insert a feeler gauge between the contacts. Owing to the initial bedding in of a new contact set, the gap may need resetting. If so, slacken the two screws which secure the fixed contact plate. Re-position the plate, which has two slotted holes and rotates about the contact breaker lever pivot post, until the gauge 0,015 inch can be inserted, as a sliding fit, between the contact. Retighten the two screws. After adjustment recheck the gap to see that no movement has taken place whilst tightening the screws.

Lubrication (every 6,000 miles)

Do not allow oil or grease on or near the contacts when carrying out the following.
Remove the moulded cover and withdraw the pivot arm. To lubricate the cam bearing, inject a few drops of thin machine oil into the rotor arm spindle. Do not slacken or remove the screw located inside the spindle a passage is provided beneath the screw bead to allow the lubricant to reach the cam bearing. Lightly smear the outside faces of the cam with Mobilgrease 2 or with engine oil.
For centrifugal timing control lubrication inject a few drops of thin machine oil into the aperture in the contact breaker base plate through which the cam protrudes.
For contact breaker pivot place a spot of Mobilgrease 2 or clean engine oil on the top of the contact breaker lever pivot post. Refit the rotor arm, carefully locating its moulded projection in the spindle keyway and pushing it on as far as it will go. Refit the moulded cover.

Cleaning (every 6,000 miles)

Remove the moulded cover and clean the inside and outside with a soft dry cloth. Pay particular attention to the space between the terminals. Check the high tension pick-up brush to make sure it moves freely in its holder. Remove the rotor arm and examine the contact breaker. Rough, burned or blackened contacts can be cleaned with fine carborundum stone or emery cloth. After cleaning, remove any grease or metallic dust with a petrol-moistened rag. 
Contact cleaning is made casier by removing the lever to which the moving contact is attached. To do this, slacken the low tension terminal nuts and lift the lever from its pivot and the end of the spring (wich is slotted)

 

   

from the terminal. After cleaning and trimning the contacts, smear the pivot post with Rogosine Molybdenised non-slip oil or with Mobilgrease 2. Reassemble the contact breaker and check gap setting as previously described. Refit the rotor arm and moulded cover.

Performance Data 

with contact breaker gap 0,015 inch. contact breaker spring tension measured at contact 18 to 24 oz.. capacitor 0,18-0,23 mfd. Advance due to automatic timing control, run distributor at 800 r.p.m. Advance to be 11 max. Check advance at following decelerating speeds: 550 r.p.m. advance to be at 450 r.p.m. 5-1/2 -> 8-1/2. at 300 r.p.m. 0-> 3. No advance below 200 r.p.m.

Contact breaker contacts must be renewed as a pair and not individually. The gap must be set to 0,015 inch and rechecked after 500 miles.

 

N2

BATTERY MAINTENANCE

Wipe away any foreign matter or moisture from the top of the battery, and make sure the connections and the fixing are clean and tight. About every 1.000 miles or once a month, and more often in hot wether, examine the level of the electrolyte in the cells. If necessary add distilled water to bring the level up to the top of the separator guard. The use of a Lucas battery filler will be found helpful in this topping-up process, as it ensures that the correct electrolyte level is obtained automatically and also prevents distilled water from being spilled over the battery top. Distilled water should always be used for topping up. In an emergency however, drinking water, clean rainwater or melted snow may be used. Salt water, chlorinated water, chemically-softened water and stagnant water must not be used. 
Never use a naked light when examining a battery, as the mixture of oxygen and hydrogen given off by the battery when on charge, and to a lesser extent when standing idle, can be dangerously explosive.
Examine the terminals and, if they show an oxide film, scrape clean and coat with petroleum jelly. Make sure the connections are clean and tight. If the cable connections are removed from the battery lugs for any purpose, or refitting, fill the screw with petroleum jelly, both before and after fitting the self-tapping screw. If the connections are fitted too tightly on the tapered battery posts, difficulty may be experienced when they have to be removed. It is advisabie to check the state of charge of the battery occasionally by measuring the specific gravity of the electrolyte in each of the cells by means of a hydrometer. The specific gravity of the electrolyte in a cell of serviceable condition will rise during charging, and fall during a discharging period.

 

Measure the specific gravity of the acid in each cell in turn with the hydrometer. To avoid misleading readings, do not take hydrometer readings immediately after topping up. The readings given by each cell should be approximately the same. If one cell differs appreciably from the others, an internal fault in the cell is indicated. The appearance of the electrolyte drawn into the hydrometer when taking a reading gives an indication of the state of the plates. If the electrolyte is very dirty, or contains small particles in suspension. It is possible that the plates are in a bad condition. Specific gravity of electrolyte (corrected to 60F): fully charged. 1,270 - 1,290; about half discharged, 1,190 - 1,210, completely discharged, 1,110 - 1,130.
The specifick gravity of the electrolyte varies with the temperature so for convenience in comparing specific gravities, it is always correct to 60F, as follows: for every 5F below 60F deduct 0,002 from the observed reading to obtain the true spceific gravity at 60F. For every 5F , above 60F add 0,002 to the observed reading to obtain the true specific gravity at 60F. The temperature must be that indicated by a thermometer actually immersed in the electrolyte, and not the air temperature. Compare the specific gravity of the electrolyte with the values given in the table and so ascertain the state of charge of the battery.
Never leave the battery in a discharged condition for any length of time. Have it fully charged and every fortnight give it a short freshening charge to prevent any tendency for the plates to become permanently sulphated.

Discharge Test

A heavy discharge tester consists of a voltmeter. 2 or 3 volts full-scale, across which is connected a shunt resistance capable of carrying a heavy current. Pointed prongs are provided for making contact with the intercell connections. A good cell will maintain a reading of 1,2 - 1,5 volts. depending on the state of charge, for at least 6 seconds. If however, the reading rapidly falls off, the cell is probably defective. This test should not be carried out immediately after the vehicle has completed a journey. Otherwise a misleading reading may be obtained. 
A battery that shows a general falling-off in efficiency, common to all cells, wilt often respond to the process known as 'cycling'. This process consists of fully charging the battery and then discharging it by connecting it to a lampboard or other load, taking a current equal to tbe charging current. The battery should be capable of providing this current for at least 7 hours before it is fully discharged, as indicated by the voltage of each cell falling to 1,8???. If the battery discharges in a shorter time repair the cycle of charge and discharge.

Preparing New, Unfilled, Uncharged Batteries

Batteries should not be filled with acid until required for initial charging. The specific gravity required for Britain

     

and climates ordinarily below 90F (32C) is 1,270, and for climates frequently over 90 (32C) is 1.210 (both as at 60F). 
Electrolyte of the specific gravity required is prepared by mixing distilled water and concentrated sulphuric acid, usually of 1,835 SG. the mixing must be carried out either in a lead-lined tank or in a suitable glass or earthenware vessel. Slowly add the acid to the water, stirring with a glass rod. Never add the water to the acid, as the resulting chemical reaction causes violent and dangerous spurting of the concentrated acid. The approximate proportions of water are 2,8 volumes of water to obtain specific gravity 1,270. and for 1,210 4,0 volume of water. 
Heat is produced by the mixture of acid and water and the electrolyte should be allowed to cool before taking hydrometer readings or pouring the electrolyte into the batterry. However, the temperature must not be below 32F. 
Carefully break the seals in the filling holes or remove the moulded pegs from the vent plugs and half-fill each cell with electrolyte. Allow the battery to stand for at least six hours (in order to dissipate the heat generated by the chemical action of the acid on the plates before continuing the filling to the top surface of the separator guard. Allow to stand for a further two hours and then proceed with the initial charge at the rate of 1,75 amps. until the voltage and specific gravity readings show no increase over five successive hours readings. This will take from  40 to 80 hourss. Some harmless frothing may occur during the first few hours.  This can be minimised by reducing the charging current. Conversely, frothing will be increased if the specified charging rate is exceeded.

This charge should not be broken by long rest periods.

If however, the temperature of ay cell rises above the 100F (3770C) in this climate (hot climates 120F) the charge must be interrupted until the temperature has fallen at least 10F below that figure. At the end of the charge carefully check the specific gravity in each cell to ensure that when corrected to 60F. it lies within the specified limits. If any cell requires adjustment, some of the over-strong electrolyte must he syphoned and replaced by distilled water or, if too high by acid of the strength used for filling in. Then continue the charge for an hour or so and again check the specific gravity. Syphon-off any electrolyte that may be above the top of the separator guard.

Preparing New Dry-charged Batteries For Service

Carefully break, the seals in the drilling holes and fill each cell with correct specific gravity acid to the top of the separator guard in one operation. The temperature of the filling room, battery and acid should be maintained at between 60F and 100F.

 

N3

DYNAMO LUBRICATION AND MAINTENANCE

Every 12.000 miles or every year, whichever occurs first, inject a few drops of high quality SAE 30 engine oil into the hole marked 'oil' at the end of the C.E. bearing housing.

Brushgear 
At every second lubricator period the generator should be removed from the engine and the brushgear inspected by a competent autoobile electrician.

Dynamo belt adjustment
Occasionally inspect the generator driving belt and, if necessary adjust to take up any undue slackness by slackening the fixing nuts and turning the generator on its mounting. Avoid overtightening the belt. The tension needed being just enough to drive without slipping. See that the machine is properly aligned, otherwise undue strain will be thrown on the generator bearings

General
The dynamo is C40-1. part No. 22700. The generator is a shunt wound, two-pole. two-brush, ventilated machine, arranged to work in conjunction with a Lucas regulator unit. Holes in each end of the bracket allow a pulley-mounted fan to draw cooling air trough the generator. This machine is designed for use with a  5-inch diameter fan ,and current voltage control under which circumstances its maximum output of 22 amps. can be safely taken. When a 4-1/2 inch diameter fan is used the maximum output must be limited to 20 amps.
The effective output is slightly reduced when compensated voltage is used with either fan size.

Brushgear (Checking with Yoke Removed)
Lift the brushes op into the brush boxes and secure them in that position by positioning the brush spring at the side of the brushes. Fit the commutator end bracket over the commutator and release the brushes.

Sabra Handbook Pic N 01

     

Hold back each of the brush springs and move the brush by pulling gently on its flexible connector. If the movement is sluggish, remove the brush from its holder and ease the sides by lightly polishing on a smooth file. Always refit brushes in their original position. Badly-worn brushes must be replaced, and the new brushes must be fitted and bedded to the commutator. The minimum permissible length of the brush is 9/32 inch. If the tension is low on the brush springs, they must be replaced.

Sabra Handbook Pic N 02

To remedy a badly worn fabricated commutator, undercut the insulators between the segments to a depth of 1/32 inch. Then take a light cut with a very sharp (preferably diamond-tipped) tool. If a non-diamond-tipped tool is used for machining the commutator should afterwards be lightly polished with a very fine glass paper, never emery cloth. Whilst the C40 Generator was designed to accommodate a commutator of moulded construction, initial production also included machines having commutators of the older fabricated type described in the previous paragraph.

Sabra Handbook Pic N 03

 

Moulded commutators can be recognised by the exposed end being quite smooth unlike that of fabricated commutators from which a metal rollover and an insulating cone protrude. A moulded commutator can be set skimmed during service. but care must be taken to see that the finished diameter is not less than 1,50 inch. This operation should be carried out by a skilled automobile electrician. If the moulded commutator cannot be completely cleaned up without going below the specified diameter it should be replaced.

Sabra Handbook Pic N 04

Armature
Indication of an open-circuited armature winding will be given by burnt commutator segments.  If armature testing facilities are not available, an armature can be checked by substitution.  To separate the armature shaft from the drive end bracket, press the shaft out of the drive end bracket bearing. When fitting a new armature, support the inner journal of the ball bearing, using a mild steel tube of suitable diameter whilst pressing the armature shaft firmly home.

Sabra Handbook Pic N 05

     
Sabra Handbook Pic N 06

Removing and Dismantling the Dynamo 
First disconnect the leads from the D and F terminals of the dynamo. Then remove the fan belt. Unscrew the three bolts securing the dynamo to the dynamo bracket attached to the cylinder head. 
Take off the driving pulley. Remove the terminals from 'output' and 'field', unscrew the two through bolts using if available, a wheel-operated screwdriver. As the bolts are being withdrawn, remove the brush housing, the driving end bracket and armature assembly can then be removed from the yoke. 
To reassemble, reverse the dismantling operations. Before reassembly, see that the ball bearing at the end is clean and well-packed with high-melting-point grease. 
Major overhauls of the dynamo should be carried out by a competent automobile electrician.

N4

THE CONTROL BOX

The control box controls the cut-out and voltage regulator. The regulator controls the dynamo output in accordance with the load on the battery and state of charge. Should the battery be discharged, the output of the dynamo will be high, thus giving the battery a quick charge and bringing it back to its normal state with the minimum of delay. However, if the battery is fully charged, the dynamo is arranged to give a small charge, which is sufficient to keep it in good condition without causing damage to the battery by overcharging. The regulator controls the dynamo, to give a boosting charge when the engine unit is first started up, thus quickly restoring the battery energy used when starting.
The cut-out is an automatic switch for connecting and disconnecting the battery with the generator. This is essential, otherwise the battery would discharge through the generator when the engine is stopped or running at low speed.

Regulator Checking and Electrical Setting

All settings are accurately adjusted before control boxes leave the factory and must not be disturbed unnecessarily. If the battery does not keep in a charged condition, or if the dynamo output doesn't fall when the battery is fully charged, it may be advisable to check the setting and if necessary to readjust. When the battery is in a low state of charge, it is essential, before altering the regulator settings to ascertain that its condition is not due to a battery defect or a slipping dynamo belt. 

  Sabra Handbook Pic N 07

The checking and adjusting should be completed as quickly as possible to avoid errors drue to the heating of the shunt coil. 
This operation can be carried out without removing the cover of the control box. Connect a first-grade 0,20 moving-coil voltmeter between control box terminals D and E. Remove control box cover in order to note the instant of contact closure. Alternatively. switch on an electrical load such as a pair of headlamps when the instant of contact closure wilt be indicated by a slight flick in the voltmeter reading.
Start the engine unit and slowly increase its speed. Observe the voltmeter pointer, if the flick occurs outside the limits 12,7 -> 13,3 volts, an adjustment must be made. Stop the engine.
For voltage adjustment, remove the control box cover. Turn the control relay adjustment screw (clockwise to raise the setting or anti-clockwise to lower it) until the correct setting is obtained. Recheck the setting by increasing the engine speed from zero. Restore the original connections and refit the cover.
For drop-off adjustment, disconnect the cables from the control box terminals A and A1 and join these cables together, connect a first-grade 0,20 moving-coil voltmeter between terminal A or Al and earth.
Start the engine and run up to speed. Slowly decelerate and observe voltmeter pointer.
Opening of the contacts, indicated by the voltmeter pointer dropping to zero should occur between the limits 8,5 -> 11,0 volts. If the drop-off occurs outside these limits, an adjustment must be made. In this event continue as follows. Stop the engine and remove the control box cover. Adjust the height of the fixed contact by carefully bending to reduce the drop-off voltage or away from it to raise the drop-off voltage. Recheck the setting and, if necessary, readjust until the correct drop-off setting is obtained. Restore the original connections and refit cover.

     

Cleaning Contacts

To clean the voltage regulator contacts, use a fine carborundum stone or silicon carbide paper. To clean the cut-Out relay contacts, use a strip of fine glass paper, never carborundum stone or emery cloth.

Sabra Handbook Pic N 08

N5

THE FUSE UNIT

The fuse marked 2 (formerly A2) protects those accessories which operate irrespective of the ignition being on or off, the electric horn is in this category. The fuse marked 4 (or A4) protects the accessories which are connected to operate only when the ignition is switched on, namely, petrol gauge, flasher units, stop lamps and windscreen wiper
The above units protected by these fuses can easily be identified by referring to the wiring diagram.  A blown fuse is indicated by the failure of all the units protected by it, and confirmed by examination of the fuse, which can be easily withdrawn from the spring clip in which it fits.  If it has blown, the broken ends of the wire will be visible inside the glass tube.  Before replacing a blown fuse inspect the wiring of the units which have failed for evidence of a short circuit or other faults which may have caused the fuse to blow; remedy the cause of the trouble.  It is important to use only the correct replacement fuse, i.e. 35 amp; the fuse value is marked on a coloured paper slip inside the tube.

 N6

  THE STARTER MOTOR

 The starting motor is a series-parallel wound four pole four brush high-speed machine, fitted with a pinion which is mounted on a quick start threaded sleeve.  The pinion engages with a ring gear fitted to the flywheel.  The operating button is mounted on the instrument panel.  
The following points should be observed when starting the engine unit:

  Sabra Handbook Pic N 09
  1. See that the controls are properly set.

  2. Press the starter button and release immediately the engine fires.

  3. Do not operate the starter when the engine is running. If the engine does not fire immediately, allow it to come to a stop before pressing the starter button again.

  4. Do not run the battery down by repeatedly pressing the starter button when the engine will not start.

  5. Do not use the starter motor to move the vehicle during a temporary breakdown. 

The starter will not require any attention during normal operation.

Testing on the vehicle
In the following test it is assumed the battery is in a fully-charged condition. Switch on the lamps and press the starter button. If the lights go dim, but the starting motor is not heard to operate, the current is probably flowing through the starting motor winding but the armature is not rotating. Check for an abnormally stiff engine or for the starter pinion being meshed permanently with the ring gear on the flywheel, that could be caused 

Sabra Handbook Pic N 10

by the starter being operated while the engine was still moving, if so, the starter motor may have to be removed from the engine for examination (see below also). Should the lamps retain their full brilliance when the starter button is operated check the circuit for continuity from battery to starting motor via the starter switch, and examine the connections at these units. If the supply voltage is found to be applied to the starting motor when the

     

switch is operated, an internal fault in the motor is indicated and the unit must be removed from the engine unit for examination. 
Sluggish or slow action of the starting motor may be due to a discharged battery or to a loose connection forming a high resistance in the motor circuit. If the motor is heard to operate, but does not crank the engine, indication is given of damage to the drive. 
Difficulty experienced with the starter not meshing corectly with the flywheel could be due to dirt or engine oil on the starter drive, preventing the free movement of the pinion and barrel assembly on its sleeve, the sleeve pinion should be washed with paraffin. Alternatively the drive may have been damaged owing to misuse.
Should the starter pinion become jammed in mesh with the flywheel, it can usually be freed by turning the starter armature by means of a spanner applied to the shaft extension at the commutator end.

N7

REMOVING THE STARTER FROM THE ENGINE AND DISMANTLING

Every 12.000 miles the commutator and brushgear should be examined. It is advisable to remove the starter from the engine for this purpose. Disconnect one of the battery cables at the battery to avoid any danger of causing short circuits. 
Disconnect the cable from the starter motor, remove the two bolts securing the starter motor to the engine plate and clutch housing, the starter motor can then he removed. Should any of the parts of the drive be worn or damaged they must be replaced, the drive is dismantled by first removing the split pin from the nut at the end of the starter drive. Hold the squared starter shaft extension at the commutator end by means of a spanner and unscrew the shaft nut. Lift off the main spring, buffer wasber, remove the corrugated retaining ring from the inside of the pinion barrel assembly, control nut, sleeve and restraining spring will now slide off. Withdraw the splined washer from the armature shaft and remove the pinion and barrel.

Sabra Handbook Pic N 11

 

The assembly of the drive is a reversal of the dismantling procedure.

Should either the control nut or screwed sleeve be damaged, then a replacement assembly of screwed sleeve and control nut must be fitted. These components must not be renewed individually.

Remove the cover band, hold back the brush springs and lift the brushes from their holders. Remove the nuts from the terminal post which protrudes from the commutator end bracket. Unscrew the two through bolts from the commutator end bracket and remove the commutator end bracket from the yoke. Remove the driving end bracket and drive from the starting motor yoke. If it is necessary to remove the armature from the driving end bracket it can be done by means of a hand press, after the drive bas been dismantled. Reassemble by reversing the above procedure.

Commutator
The commutator should be clean, free from oil or dirt and should have a polished appearance. If it is dirty, clean by pressing a fine dry cloth against it, while the starter is turned by hand by means of a spanner applied to the squared extension shaft. Access to the squared shaft is gained by removing the thimble-shaped metal cover. Should the commutator be very dirty moisten the cloth with petrol. 
The insulators between the commutator segments MUST NOT BE UNDERCUT

Brushgear
Remove the metal band cover and examine the brushes, check that these move freely in their holders by holding back the brushes spring and pulling gently on the flexible connections.

Sabra Handbook Pic N 12

     

If a brush is inclined to stick, remove it from its holder and clean the sides with a petrol-moistened cloth. Be careful to replace brushes in their original position in order to retain the bedding. Replace the brushes. 
Two of the brushes are connected to terminal eyelets attached to the brush boxes on the commutator end bracket, and two are connected to the aluminium field coils. If the brushes are worn so that they do not bear on the commutator or if the flexible connections are exposed on the running face, they must be replaced. To do this proceed as follows. Cut off the original brush flexible 1 inch (3 mm approx.) from the aluminium. Clean up and tin the original resistance brazed joint. Open out the loop of the replacement brush flexible. Tin the loop, taking care not to allow any solder to run towards the brush. Place the original joint within the loop. Squeeze up and solder. The brushes are pre-formed so that the bedding to the commutator is unnecessary.

N8

IGNITION

Distributor 
A centrifugally-operated timing control mechanism is mounted on the driving shaft immediately beneath the contact breaker. The mechanism consists of a pair of spring loaded governor weights linked by lever action to the contact breaker cam. At low engine speed the spring force maintains the cam in position in which the spark is slightly retarded. At high engine speed the governor weights swing outwards to turn the contact breaker cam thereby advancing the spark. 
The capacitor is of metallised paper construction, and bas the property of being self-healing. Thus in the event of a dielectric breakdown occuring, the metallic film around the point of rupture is vaporised away by the heat of the spark. In this way permanent short circuits are prevented.
The centre portion of the resistive pick-up brush is made of a hard resistive carbon compound whilst the end portions are of a soft carbon. Since the brush is in circuit between the ignition coil and distributor high tension terminals this produces a measure of radio and television interference. On no account must a short non-resistive brush be used to replace a long resistive brush.

Ignition Timing 
Remove the sparking plugs and rotate the engine until the raised timing boss on the cylinder front cover and the notch on the crankshaft pulley rim coincide. At this position, the No. 1 piston will be at Top Dead Centre on the compression stroke. With the distributor cap removed, ensure that the rotor arm is facing the offset slot in the drive shaft in the cylinder block. Before refitting the distributor to the engine, hold the distributor body so that the knurled micro adjuster is parallel to the engine and position the rotor  arm in 

  Sabra Handbook Pic N 13

line with the low tension terminal. Refit the distributor and secure the body clamp plate to the cylinder block by means of the two clamping screws. Check that the micro adjusting nut is set to the fourth line on the graduated scale which is the zero setting. Having refitted the distributor, the body clamp bolt should be slackened and the distributor head turned clockwise until the contact points are just breaking. The exact position can be determined by inserting a very thin piece of paper between the points when they are fully closed, and gently pulling on the paper whilst the distributor head is being turned. When the paper can be eased out this will indicate that the points are about to break. 
Tighten the clamp bolt and re-check the adjustment.

Coil 
The ignition coil requires no attention other than seeing the terminal connections are tight, and that the extension is kept clean, particularly between the terminals.

H.T. Cables

The high tension cables must be carefully examined, and any which have the insulation cracked, perished or damaged in any way must be replaced with rubber-covered ignition cable. The method of connecting the cables to the coil and distributor cap is to thread the knurled moulded nut over the cable, bare the end of the cable for approximately 1 inch, thread the wire through the copper washer removed from the original cable, bend back the wire strands, screw nut into its terminal.

     

Ignition Waming Lamp Switch
The ignition switch, besides forming a means of starting and stopping the engine unit, is provided for the purpose of preventing the battery being discharged by the current flowing through the coil windings when the engine is stopped. A red warning lamp is provided in the instrument panel which lights immediately the engine is switched on, also whilst the engine is ticking over or is stationary, reminding the driver to switch off. Should the warning lamp bulb become defective, this will in no way affect the ignition system, but should be renewed as soon as possible, in order to safeguard the battery.

N9

THE FLASHING LAMP DIRECTION INDICATORS

The flasher unit model F15 is housed in a small cylindrical container, in which the alternate heating and cooling of an actuating wire causes the operation of a main armature and associated pair of contacts in the flasher lamp supply circuit. At the same time, a secondary armature operates pilot contacts which cause a warning light to flash when the system is functioning correctly. Failure of warning light to flash will indicate a fault in the system. 
Flasher units cannot be dismantled for rectification; a defective unit must be replaced, care being taken to reconnect as the original.

Switch 
There is a two-way-and-off switch for controlling the flasher lamps. The connection should be checked occasionally and tightened if loose. Bulb is Lucas No. 987, 12- volt, 2-2-watt, M.E.S. cap.

N10

WINDSCREEN WIPER

The motor and gearbox unit is mounted in the engine compartiment on three parts cast integrally with the unit body. The rotary motion of the motor armature is converted to the reciprocating motion of the cable rack by means of a single-stage worm and nylon gear reduction drive. A connecting rod and crosshead in the gearbox actuate the cable rack which passes through protective outer tubing to the wheel boxes. The rack consists of a flexible core of steel wire wound with a wire helix which engages with a gear in each wheel box and thus transmits the reciprocating motion to the wiper arm spindles. To start the windscreen wiper, turn the rotary switch on the left hand side of the instrument panel. The arms and blades return automatically to the parking position whatever their whereabouts when switched off. As the gearbox, cable rack and wheelboxes are greased during manufacture, they do not require any periodic lubrication.

 

Replacement of Arm Blade Assembly 
The screw securing the arm and blade assembly is designed so that it also takes the form of an extractor. To remove the arm and blade assembly, slacken the flxing screw from the wiper spindle.

N11

LIGHTING

General 
The headlights are sealed beam units. The filaments are sealed in the glass unit which consists of the lens and the reflector. In the event of a bulb blowing, only the complete unit is replaceable.

Lamp Rim Removal 
To remove the lamp rim, unscrew the securing screw at the base of the rim. The rim can then be lifted off, leaving the glass bulb and reflector, which are permanently sealed together as a unit, still in position. The replacement of the lamp rim is the reverse procedure.

Scaled Beam Unit Removal 
To remove the unit slacken the three screws securing the inner bezel. The unit can then be lifted out and the connecting plug at the rear of the unit disconnected. When removing, turn the unit so that it can be drawn away leaving the securing screws in position. The elongated slots on the bezel have one end slightly enlarged to facilitate this.

Replacement of Sealed Beam Unit
The reassembly of the unit is a reversal of the above instructions.

Headlamp Alignment 
The headlamps should be set so that the main driving beams are straight ahead and parallel with the road surface and with each other. If adjustment is necessary, remove the lamp rim as previously described. Adjust both lamps to the correct position in the vertical plane by means of the vertical adjustment screw at the top of the seal beam unit. To raise the beam, the screw must be turned in a clockwise direction and to lower the beam, in an anti-clockwise direction. The two screws positioned on either side of the unit are for the horizontal adjustment of the beam. Alignment should be carried out with the empty car standing on a level surface at a distance of 25 feet from a white wall or screen. The wall should be in semi-darkness and shielded from direct light so that the bright spots from the beamlamps can be clearly defined.

Number Plate Lamp
Remove the two front-cover screws to gain access to the bulb. The bulb is Lucas No. 989, 12-volt, 6-watt, M.E.S. cap.

You might want to have a look at a thorough description of wiper motor etc.     
     

Oil Waming Lamp 
The oil warning lamp should light only when the engine is at rest with the ignition switched on, and immediately the engine reaches speed should become extinguished, thus indicating that the oil is being circulated under pressure in the engine lubricating system. To replace the bulb withdraw the bulb holder from its housing at the rear of the panel. The bulb is Lucas No. 987, 12-,volt, 2-watt, B.A.7.S cap.  

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Ignition Waming Light 
The ignition warning light serves the dual purpose of reminding the driver to switch off the ignition before leaving the vehicle and of acting as a no-charge indicator. It should only operate with the engine at rest or turning over slowly, and should become extinguished immediately the engine revolutions are increased; failure to do so indicates a fault in the charging circuit. The bulb is Lucas No. 987, 12-volt. 2-watt, B.A.7.S. cap.

Flasher Lamp 
Access to the rear flasher lamp bulb is by removing the two screws securing the lens. For access to the front flasher lamp, peel back the rubber surround to release the rim and lens. The bulb is Lucas No. 382, 12-volt, 21-watt, S.B.C. cap.

Side Lamp 
To gain access to the bulb, peel back the rubber surround to release the rirn and lens. the bulb is Lucas No. 207, 12-volt, 6-watt, S.B.C. cap. Stop and Tail Lamps Access to the bulb is gained by rernoving the two screws securing the lens. the bulb is Lucas No. 380, 12-volt, 6121 -watt, S.B.C. cap.

Cleaning Lamps 
Chromium-plated surfaces should be washed with plenty of water and when the dirt is removed they should be polished with a chamois leather or soft dry cloth. Do not use metal polishes on chromium plating.

Electric Horn 
The vehicle has two horns, one high and one low, positioned left and right in front of the radiator. All horns before being passed out of the works are adjusted to give their best performance and will give a long period of service without attention. Should either horn fail or become uncertain in performance, ascertain that the trouble is not due to faulty wiring, or discharged battery, a short circuit in the born will cause the fuse to blow. If the fuse is blown examine the wiring for fault, rectify, then replace fuses. 
To adjust either hom remove the cover plate which is secured by one fixing screw at the rear of each horn; the points can then be adjusted. If, after this operation bas been carried out, the horn is still at fault it should be returned to a Lucas Agent for rectification.

  N12

LOCATION AND REMEDY OF FAULTS

Every precaution is taken to minimise all possible causes of trouble; failure may develop through lack of attention to equipment or damage to wiring. The sources of many troubles are by no means obvious, often a considerable amount of deduction from the symptoms is needed before the cause of the trouble can be traced. The engine may not respond when the starter switch is depressed, but the starter motor is dependent on the battery, so that a faulty connection or a flat battery could be one cause of this faiture. If the battery should be flat this would be due to the dynamo failing to charge the battery, due to a slack fan belt or a faulty connection in the charging circuit. If after carrying out the examination, it is not possible to trace the cause of the trouble, it is advisable to contact the nearest Lucas Service Depot or Agent.

Failure of Engine to Fire 
Make sure the terminals on the battery have a good connection, also that the battery is fully charged. The simplest method of testing the battery is to ensure that the lamps give a good light, and that the starter will turn the engine. Should the battery be flat, this must be recharged from an independent electrical supply. 
Make sure the contacts are correctly set for starting. 
Remove the cable from the centre terminal of the distributor cap and hold this so that the end is about a 1 inch away from any metal part of the chassis whilst the engine is turned over slowly. If the spark jumps the gap regularly, the coil and distributor are functioning correctly. 

Sabra Handbook Pic N 14

     

The sparking plugs should be examined. If these are clean and the gaps correct, the trouble could be due to carburettor or petrol supply. 
If the coil does not spark in the test, check for a fault in the low tension wiring.
Remove the distributor cap. If no spark occurs between the distributor contacts when quickly separated by the fingers, with the ignition switched on, examine all cables in the ignition circuit for a faulty wire, making sure that all connections are tight.
If no fault is found with the wiring and connections, examine the contact breaker points, they may require cleaning and gap resetting to 0,015 inch.

Engine Misfires 
Ensure that the distributor contacts are thoroughly clean, and the gap correctly set at 0,015 inch. Run the engine at an idling speed slightly above normal, short-circuit each sparking plug in turn, using an insulated screwdriver placed across the plug terminal and contacting the cylinder head. When a faulty plug is short-circuited, this will not cause a noticeable change in the running note, whereas the shorting of a sound sparking plug will increase the roughness of the engine unit. Having located any faulty cilinders stop the engine, remove the cabine from the sparking plug terminal, restart the engine, hold the cable about 1 inch from the plug terminal or cylinder head, if the sparking is strong and regular, the fault lies with the sparking plug which should be removed, cleaned, and the gap reset to 0,018 inch, or be replaced with a new plug. 
Should there be no spark, or only a weak and intermittent spark, examine the cable from the plug to distributor.
Renew the cable if the rubber is cracked or perisbed.
Clean the distributor moulded cover and check the free movement of the carbon brush. Should the brush need replacing, make sure the correct type is obtained. On no account must the standard

Sabra Handbook Pic N 15

 

non-resistive brush be fitted, as this is too short for use with the model 1/2A4 distributor and would not make contact with the rotating electrode. If tracking has occurred, this will be indicated by a thin black line, usually between two or more electrodes; a replacement distributor cover must be fitted. If tests show all four plugs to be sparking regularly, the trouble could be due to valve seating or burnt valves, carburettor, or petrol supply. 

Battery in Low State of Charge 
This will be indicated by lack of power when starting, poor lighting, and hydrometer readings below 1,190 1,120. It could be due to the dynamo not charging, giving a low intermittent output, or the control box requiring resetting. The ignition warning light will not go out if the dynamo is not charging, or will flicker on and off in the event of an intermittent output. 
Examine the charging and field circuit wiring, tighten any loose connections, replace any broken cables. Pay particular attention to the battery connections. Make sure the dynamo driving belt is correctly adjusted; slackness can be taken up by slacking off the dynamo fixing bolts to enable the dynamo to be turned in its mounting bracket, retighten bolts after carrying out the necessary adjustment. 
If the cause of the trouble is not apparent the equipment should be examined by a Lucas Service Depot or Agent.

Overcharged Battery 
This will be indicated by burnt out bulbs, frequent need for the topping up of the battery and high hydrometer readings.
Check the charging current when the car is running steadily with a fully charged battery, with all lights and accessories in use the charge reading should be 1 amp. If in excess of this value the regulator setting should be tested and adjusted. If necessary, by a Service Depot or Agent.

Starter Motor 
If the starter motor lacks power or fails to turn the engine, first check to ensure the trouble is not due to a flat battery. Examine the connections to the battery, starter, and starter button, seeing that these are tight and the cables connecting these units are not damaged. A further possibility is that the starter pinion may have jammed in mesh with the flywheel, although this is not a common occurrence. To disengage the pinion, rotate the squared end of the starter shaft by means of a spanner. Should the starter operate and not crank the engine, this fault could be caused if the pinion and barrel assembly of the starter drive is not allowed to move along the screwed sleeve into engagement with the flywheel, possibly because engine oil or dirt has collected on the screwed sleeve. Thoroughly clean the sleeve, either with petrol or paraffin.

     
Sabra Handbook Pic N 16
 
     

Lighting Circuit 
If the lamps give insufficient illumination, test the battery to ensure it is properly charged, if recharging is necessary this should be carried out by either a long period of daytime running or from an independent electric supply. Check the setting of the lamps. Should the bulbs be discoloured from long service these should be replaced. 

 

If the lamps light when switched on, then gradually fade, check as paragraph one. Should the brilliance of the lights vary with the speed of the car, check as paragraph one. Also examine the battery connections, seeing that they are tight; replace any faulty cables.

     

Common Technics