Lucas

Lucas Electrical Limited Parts and Service DivisionGreat Hampton Street Birmingham B18 6AU

PTC2Publication No. PLT6081B

© Lucas Electrical Limited 1978Printed in England 10M/478/DL

RECOMMENDED TEST EQUIPMENTD.C. Moving Coil Voltmeter Scale 0-20VHydrometerNote:1. Test figures quoted are typical only2. During testing the-engine should be cranked without starting:

Petrol — Disconnect coil to distributor LT leadDiesel — Operate engine stop control

EST:

HYDROMETER READING

ESULT:

Clean and tight

1.110-1.130

1.230-1.250

1.270-1.290

3 BATTERY VOLTAGE, ON LOAD

Below 1.230Recharge and then test

1.290.

Loose and/or dirtyRectify

TO IGN/Sswr

If starter does not motor checksolenoid operation, supply cablesand earth connections. Rectify.

Should be approx:Inertia 10.5VPre-Engaged 10.0V

TEST 4elow expected voltage, check

battery state of charge and if lowretest with good substitutebattery

TEST

I

A VOLTAGE AT SOLENOID OPERATING TERM___—, . f —y^-^s ^•r'_ Should be:Similar voltage toprevious test

TEST 5

voltage is lower than in previoustest, check ignition/starterswitch, all cables and connectionsetc. Rectify ^^^J

See also note below

Should be:Within 0.5V of voltagein test 3

CircuitSatisfactory

Voltage more than 0.5V belowreading in test 3

TEST

Should be:Approx zero voltage

ID CONTACT

TOSWITCH

7 VOLTAGE DRO• TO BATTERY

TOSTARTER

Should be:Approx zero voltage.If zero voltage is shown, solenoid issatisfactory and a fault existselsewhere in the circuit. Check allinsulated line cables andconnections. Rectify.Recheck as test 6

If above 0.25VReplace solenoid

TEST!

8 VOLTAGE DROP, EARTH LINEShould be:Approx. zero voltage.

If above 0.25V check all earthconnections including chassis/ngine bonding strap.

NOTE: Starter circuit may incorporate an additional solenoid in the operating line (mainlycommercial vehicle applications). Check operation of this solenoid.

CRANK! To STARTER SOLENOID OPERATING ' \O BATTERYTERMINALENGINE V1, V2 Must show same voltage

as test 3. If lower check supplycables from battery and starterswitch.V3 should be zero. If more thanzero is shown while cranking,replace solenoid.If battery voltage is shown whileattempting to crank the engine,check solenoid earth connections,and if satisfactory replace solenoid.