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 dome and rear view mirror reading lamps connector.
  2. Use a DMM in order to measure the resistance between terminal B of the rear view mirror reading lamps connector and ground.

Is the resistance measured within the specified range?

0-2 ohms

Go to Step 2

Go to Step 3

2

Use a DMM in order to measure the voltage between terminal C of the dome and rear view mirror reading lamps connector and ground.

Is the voltage measured equal to the specified value?

B+

Go to Step 4

Go to Step 8

3

Repair the open in CKT 750 between the dome and rear view mirror reading lamps and ground splice pack G401. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Interior Lamps System Check

--

4

Use a DMM in order to measure the resistance between terminal A of the dome and rear view mirror reading lamps connector and ground.

Is the resistance measured within the specified range?

0-2 ohms

Go to Step 5

Go to Step 6

5

Replace the rear view mirror reading lamps.

Is the repair complete?

--

Go to Interior Lamps System Check

--

6

  1. Use a DMM in order to backprobe the left IP junction block connector C3.
  2. Measure the resistance between terminal A11 and ground.

Is the resistance measured within the specified range?

0-2 ohms

Go to Step 7

Go to Step 10

7

Repair the open in CKT 156 between the left IP junction block and the dome and rear view mirror reading lamps. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Interior Lamps System Check

--

8

Use a DMM in order to backprobe the left IP junction block connector C3 and measure the voltage between terminal C4 and ground.

Is the voltage measured equal to the specified value?

B+

Go to Step 9

Go to Step 10

9

Repair the open in CKT 1732 between the left IP junction block and the dome and rearview mirror reading lamps. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Interior Lamps System Check

--

10

Replace the left IP junction block.

Is the repair complete?

--

Go to Interior Lamps System Check

--