GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

1

Did you review the Exterior Lighting Systems Description and Operation and perform the necessary inspections?

Go to Step 2

Go to Exterior Lighting Systems Description and Operation

2

Verify that the license lamps are inoperative.

Do the license lamps operate normally?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Place the headlamp switch in the HEAD position.

Is only one lamp inoperative?

Go to Step 4

Go to Step 5

4

Remove the inoperative lamp and inspect for the following:

    • An open bulb filament
    • Poor terminal contact
    • Corroded or open terminals
    • Shorted terminals

Was a problem found?

Go to Step 9

Go to Step 5

5

Test the trailer park lamps supply voltage circuit for an open, high resistance or short to ground. Refer to Circuit Testing in Wiring Systems.

Was a problem found?

Go to Step 7

Go to Step 6

6

Test the ground circuit for an open or high resistance. Refer to Circuit Testing in Wiring Systems.

Was a problem found?

Go to Step 8

Go to Step 10

7

Repair the open, high resistance or short to ground in the trailer park lamps supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 11

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8

Repair the open or high resistance in the ground circuit. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 11

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9

Replace the inoperative license lamp bulb and/or socket.

Is the repair complete?

Go to Step 11

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10

Replace the license lamp socket.

Is the repair complete?

Go to Step 11

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11

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3