GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Interior Lights Dimming Schematics

1

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

Go to Step 2

Go to Symptoms - Lighting Systems

2

  1. Turn the ignition to the RUN position.
  2. Place the headlamp switch in the PARK position.
  3. Attempt to dim the instrument panel lamps using the IP dimmer switch.

Do the instrument panel lamps dim?

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

Go to Step 3

3

  1. Disconnect the IP dimmer switch.
  2. Connect a test lamp between the signal circuit of the IP dimmer switch and ground. Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

Go to Step 5

Go to Step 4

4

Inspect for poor connections at the harness connector of the IP dimmer switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 7

Go to Step 6

5

Repair the short to battery voltage in the IP dimmer switch signal circuit or in the IP lamp supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the replacement?

Go to Step 7

--

6

Replace the IP dimmer switch. Refer to Headlamp Switch Replacement .

Did you complete the replacement?

Go to Step 7

--

7

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2