GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

DEFINITION: High and low beam headlamps are inoperative on both sides of the vehicle.

1

Review the headlamp operation and perform the necessary inspections.

Did you complete the system review and inspection?

--

Go to Step 2

Go to Symptoms

2

Attempt to operate the headlamps.

Does the system operate normally?

--

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

Go to Step 3

3

  1. Turn on the headlamps.
  2. At connector C200, measure the voltage at terminal E13.

Is the measurement equal to battery voltage?

B+

Go to Step 4

Go to Step 5

4

Replace the headlamp dimmer switch.

Is the repair compete?

--

Go to Step 10

--

5

  1. Disconnect the headlamp switch.
  2. At the headlamp switch connector, measure the voltage at cavity C.

Is the measurement equal to battery voltage?

B+

Go to Step 7

Go to Step 6

6

Repair the open CKT 42 (RED) between the LIGHTING fuse and the headlamp switch.

Is the repair compete?

--

Go to Step 10

--

7

With the headlamp switch disconnected and the headlamp position selected, test the continuity of the headlamp switch between terminals C and G.

Does the test indicate continuity?

--

Go to Step 9

Go to Step 8

8

Replace the headlamp switch.

Did you complete the repair?

--

Go to Step 10

--

9

Repair the open CKT 10 (YEL) between the headlamp switch and connector C200.

Did you complete the repair?

--

Go to Step 10

--

10

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3