GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

1

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

Go to Step 2

Go to Symptoms - Lighting Systems

2

Verify that the stop lamps are inoperative.

Does the system operate normally?

Go to Testing for Electrical Intermittents in Wiring Systems

Go to Step 3

3

Test the voltage supply circuit between the STOP LAMPS fuse and the stop lamp switch for battery positive voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and complete the repair?

Go to Step 9

Go to Step 4

4

With the stop lamp switch closed, test the stop lamps supply voltage circuit at the stop lamp switch for battery positive voltage. Refer to Circuit Testing Wiring Systems.

Is battery voltage present?

Go to Step 5

Go to Step 8

5

With the stop lamp switch closed, test the stop lamps supply voltage circuit at the stop lamps for battery positive voltage. Refer to Circuit Testing Wiring Systems.

Is battery voltage present?

Go to Step 6

Go to Step 7

6

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

Did you complete the repair?

Go to Step 9

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7

Repair open or high resistance in the stop lamp supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 9

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8

Replace the stop lamp switch. Refer to Stop Lamp Switch Replacement in Wiring Systems.

Did you complete the repair?

Go to Step 9

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9

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2