Checking Instrument Lighting

UB1 Checking Voltage to Bulbs:





- Ignition off.
- Connect breakout box and check ground terminal according to "Connecting the Breakout Box". Connecting the Breakout Box
- Connect combined instrument panel.
- Ignition on.
- Switch on headlamps.
- Set the instrument lighting rheostat to maximum.

Use a voltmeter to measure between # 10 (# A10) and # 17 (# A17) on the breakout box. The voltmeter should read approximately battery voltage.

If reading is OK: UB2
If reading is incorrect: UB3

UB2 Replacing Component:
Try new instrument lighting bulbs. Service and Repair Then continue with: UB4

UB3 Checking for an Open-Circuit:





Check cable between combined instrument panel # A10 and junction point 23/300 for an open-circuit according to ZA2. Permanent Faults Then continue with: UB4

NOTE: For further information about the circuit, see Wiring Diagram.

UB4 Verification:





After carrying out the repair check that the fault has been remedied.

- Ignition off.
- Reconnect connectors, reinstall components.
- Connect combined instrument panel.
- Ignition on.
- Switch on headlamps.
- Set the instrument lighting rheostat to maximum.

Does the instrument lighting light?

Yes: Fault corrected
No: Fault not found