GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Upfitter Provision 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

Verify that the roof beacon lamp is always ON.

Does the roof beacon lamp operate normally?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Disconnect the roof beacon relay.

Does the roof beacon lamp turn OFF?

Go to Step 4

Go to Step 6

4

  1. Reconnect the roof beacon relay.
  2. Disconnect the roof beacon switch.

Does the roof beacon lamp turn OFF?

Go to Step 7

Go to Step 5

5

Test the hazard switch signal circuit of the roof beacon switch for a short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 9

Go to Step 8

6

Repair the hazard flasher signal circuit of the roof beacon relay for a short to voltage. Refer to Wiring Repairs .

Did you complete the repair?

Go to Step 9

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7

Replace the roof beacon switch.

Did you complete the replacement?

Go to Step 9

--

8

Replace the roof beacon relay. Refer to Relay Replacement .

Did you complete the replacement?

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 3