GM Service Manual Online
For 1990-2009 cars

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

1

Did you review the exterior lighting description and operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Lighting Systems

2

Place the headlamp switch in the PARK position.

Do the tail lamps illuminate?

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

Go to Step 3

3

Are the marker lamps illuminated?

Go to Step 4

Go to Marker Lamps Inoperative

4

  1. Disconnect one of the tail lamps.
  2. Probe the tail lamp supply voltage circuit with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 6

5

Repair an open or high resistance in the tail lamps ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 7

--

6

Repair an open, high resistance, or short to ground in the tail lamps supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 7

--

7

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3