GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

Connector End View Reference: Lighting Systems Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Probe the park lamp circuit at the connector that it is inoperative from upfitter connector or tractor trailer receptacle, with a test lamp that is connected to ground.
  2. Place the headlamp switch in the PARK or HEADLAMP position.

Does the test lamp illuminate?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Do the vehicles park lamps operate properly?

Go to Step 4

Go to Park Lamps Inoperative

4

Repair an open or short to ground in the park lamp voltage supply circuit. Refer to Circuit Testing and Wiring Repairs .

Did you complete the repair?

Go to Step 5

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5

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3