3233103 - K91 INSTRUMENT LIGHTS / LIGHTING DIMMER NOT WORKING

With the ignition turned on ON and the side lights on, the instruments are properly lit but the intensity is not adjustable.
Results of the tests
1CHECKING INSTRUMENT LIGHTING DIMMER BUTTONAll OKProblems metOperation
Check instrument lighting dimmer button operation ( See   E2530  INSTRUMENT LIGHTING ). Continue to Step 2 Instrument lighting dimmer button faulty Repair or replace the instrument lighting dimmer button Op.   5540C18 
2CHECKING INSTRUMENT LIGHTING DIMMER ELECTRICAL CIRCUITAll OKProblems metOperation

Check, in order:

  • Connection between speedometer and instrument lighting dimmer control
  • lighting dimmer control earth
  • connection between speedometer and other instruments
  • connection between stalk unit and instrument lighting dimmer control
( See   E2530  INSTRUMENT LIGHTING ).
Continue to Step 3 Connection brokenRestore connection
3SPEEDOMETER CHECKAll OKProblems metOperation
Check operation of the speedometer, particularly the instrument lighting dimmer function: see DESCRIPTION AND OPERATION: 5560 INSTRUMENT PANEL Continue to Step 4 Instrument not working Replace the speedometer Op.   5560B02 
4CHECK CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisFault persistsSearch for the fault starting from another symptom'