GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Interior Lights Schematics

Connector End View Reference: Master Electrical Component List in Wiring Systems.

DEFINITION: One of the following condition is present:

    • The incandescent lamps do not change intensity.
    • The Radio and the Driver Information Center's (DIC) vacuum fluorescent displays do not dim when the park lamps are turned on.

1

Did you perform the Lighting System Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

  1. Place the ignition switch in the OFF position.
  2. Turn the headlamp switch to the HEAD position.
  3. Close all of the doors.
  4. Place the IP dimmer switch in the DOME position.

Do the courtesy lamps operate properly?

Go to Step 3

Go to Courtesy Lamps Inoperative

3

  1. Place the IP dimmer switch in the OFF position.
  2. Vary the dimmer switch from minimum brightness to the full bright position.

Do the incandescent lamps vary in brightness?

Go to Step 4

Go to Step 5

4

Do all the vacuum fluorescent displays vary in brightness?

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

Go to Step 6

5

Test for a short to battery positive voltage in the instrument panel lamp supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 9

6

Do any of the vacuum fluorescent displays vary in brightness?

Go to Step 7

Go to Step 8

7

Test for an open in the step dim signal circuit to the inoperative component(s). Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 10

8

Test for an open or short to ground in the step dim signal circuit of the headlamp switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 9

9

Inspect for poor connections at the harness connector of the headlamp 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 13

Go to Step 12

10

Inspect for poor connections at the harness connector of the inoperative component. 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 13

Go to Step 11

11

Replace the inoperative component.

Did complete the repair?

Go to Step 13

--

12

Replace the headlamp switch. Refer to Headlamp Switch Replacement .

Did complete the repair?

Go to Step 13

--

13

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2