GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

Important: A short to ground will cause an open fuse(s). Before performing this diagnostic procedure, inspect the fuse(s) for an open.

1

  1. Disconnect the lamp dimmer module connector.
  2. Turn the headlight switch to the PARK position.
  3. Use a J 39200 Digital Multimeter (DMM) to measure the voltage between terminal D of the lamp dimmer module harness connector and ground.

Does the voltage measured equal the specified value?

battery positive voltage

Go to Step 2

Go to Step 3

2

  1. Turn the instrument panel dimmer switch to full intensity.
  2. Use a J 39200 DMM in order to measure the voltage between terminal B of the lamp dimmer module harness connector and ground.

Does the voltage measured equal the specified value?

battery positive voltage

Go to Step 4

Go to Step 5

3

Use a J 39200 DMM in order to measure the voltage between the INST LPS fuse CKT 9 terminal and ground.

Does the voltage measured equal the specified value?

battery positive voltage

Go to Step 6

Go to Step 7

4

Connect a fused jumper between terminal C and terminal D of the lamp dimmer module harness connector.

Do the interior lamps light?

--

Go to Step 8

Go to Step 9

5

  1. Disconnect the panel dimmer switch connector.
  2. Use a J 39200 DMM in order to measure the voltage between terminal C of the panel dimmer switch harness connector and ground.

Does the voltage measured equal the specified value?

battery positive voltage

Go to Step 10

Go to Step 11

6

Repair the open in CKT 32 between the fuse block and splice S213. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Interior Lamps System Check

--

7

Repair the open in CKT 9 between splice S216 and the fuse block. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Interior Lamps System Check

--

8

Replace the lamp dimmer module.

Is the repair complete?

--

Go to Interior Lamps System Check

--

9

Repair the open in CKT 8 between the lamp dimmer module and splice S218. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Interior Lamps System Check

--

10

Connect a fused jumper between terminal B and terminal C of the panel dimmer switch harness connector.

Do the interior lamps light?

--

Go to Step 12

Go to Step 13

11

Repair the open in CKT 32 between splice S213 and the panel dimmer switch. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Interior Lamps System Check

--

12

Replace the panel dimmer switch.

Is the repair complete?

--

Go to Interior Lamps System Check

--

13

Repair the open in CKT 44 between the panel dimmer switch and the lamp dimmer module. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Interior Lamps System Check

--