300Tdi Discovery
ELECTRICAL
3
FAULT DIAGNOSIS
1
2
3
4
SUSPECT
L
*
*
*
DISCHARGED BATTERY
*
L
L
*
IGN. SWITCH AND/OR
WIRING
*
*
L
*
COIL OR AMPLIFIER
*
*
*
H
AMPLIFIER GROUND
Key
* Expected Voltage
H Voltage higher than expected
L Voltage lower than expected
TEST 3:
Amplifier Switching
Connect voltmeter between battery positive (+ve)
terminal and H.T. coil negative (-ve) terminal.
Voltmeter should register 0 volts.
Switch ignition ’On’, voltmeter should still register 0
volts.
Crank engine, voltmeter reading should increase
when cranking, in which case proceed to Test 5.
If no increase in voltage during cranking proceed to
Test 4.