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Alfa Romeo GT Factory Service Manual (2003-2010)22 · Fault diagnosis
22 · Diagnostics

Fog lights not working

Make
Alfa Romeo
Model
GT Factory Service Manual
Year
2003–2010
Section
Lights › Fog lights not working
Fault diagnosisFog lights not working

FOG LIGHTS NOT WORKING

When the front fog lamps switch is operated with the side lights on, the front fog lamps do not work.

Results of the tests
1CHECK ON FRONT FOG LIGHT RELAY (POWER CIRCUIT)All OKProblems metOperation
On the engine compartment control unit, swap the front fog light relay with the horn relay (it is the third on the same row), and check that the front fog light works properly after the swap.Continue to Step 2Even after the swap, the front fog lights still do not workContinue to Step 3
2REPLACING HORN RELAY (POWER CIRCUIT)All OKProblems metOperation
Replace the horn relay (which was previously the front fog light relay) and check that they are working properlyEnd of diagnosis
3CHECKING FRONT FOG LIGHT RELAY SUPPLY (POWER CIRCUIT)All OKProblems metOperation

Refit the two relays in their original positions.

With the ignition on, check that the front fog light is correctly supplied by the battery.

Then connect to the relay supply from the Body Computer and check that when the front fog lights are switched on, the supply is sent to the relay.

Also check that the electrical connections between the Body Computer, the battery and the relay are not faulty See

See E2030 FOG LIGHTS

Do not connect the relay

Continue to Step 4No supply from batteryRestore the correct supply to the relay. If necessary replace the faulty components (if a fuse is involved, search for the cause of the problem)
Supply enablement not provided by the Body ComputerContinue to Step 6
Connections faulty

Restore the correct connections. See

See E2030 FOG LIGHTS

4CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation

Connect the Examiner to the diagnostic socket.

Check that there are no faults in the Body Computer

Check light operation while in active diagnosis mode

Continue to Step 5Fog lamp relay errorContinue to Step 6
Lights not activatedContinue to Step 5
5CHECK ON INDIVIDUAL LIGHTSAll OKProblems metOperation
Check the condition of individual bulbs and lampsContinue to Step 6Bulb damagedChange the bulb Op. 5540B22
Light cluster faulty

Repair or change the light unit Op.

Op. 5540B76 FRONT LIGHT CLUSTER WITH FOGLAMP ONE LH OR RH R R WITH INTERFERING PARTS REMOVED

6CHECK FOG LAMP ELECTRIC CIRCUITAll OKProblems metOperation

Check, in order:

  • front fog lamp fuse;
  • Connections between Body Computer and engine bay control unit;
  • connections between engine bay control unit and bulbs;
  • connections between Body Computer and fog lights switch;
  • Bulb earth See

    See E2030 FOG LIGHTS

Continue to Step 7Defective componentReplace the component involved (if a fuse is involved, search for the cause of the problem)
Connections broken

Restore the connections See

See E2030 FOG LIGHTS

7CHECK ON FRONT FOG LAMPS SWITCHAll OKProblems metOperation

Check the operation of the fog lamp switch See

See E2030 FOG LIGHTS

Continue to Step 8Front fog lamps switch defectiveReplace the fog light switch Op. 5540D18
8CHECK ON CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisThe fault persists

Replace the Body Computer Op.

Op. 5505A32 BODY COMPUTER - R R

Parts & tools for this job For 2003 Alfa Romeo GT

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