GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics

Connector End View Reference: Component Connector End Views

1

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

Go to Step 2

Go to Exterior Lighting Systems Description and Operation

2

  1. Turn ON the ignition, with the engine OFF.
  2. Turn ON the headlamp switch.
  3. Turn ON and OFF the headlamp high beam switch.
  4. Turn OFF the headlamp switch.
  5. Turn OFF the ignition.

Do the headlamps operate properly?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the headlamps relay.
  3. Turn ON the ignition, with the engine OFF.

Do the headlamps turn OFF?

Go to Step 4

Go to Step 6

4

  1. Turn OFF the ignition.
  2. Reconnect the headlamps relay.
  3. Disconnect the headlamp switch.
  4. Turn ON the ignition, with the engine OFF.

Do the headlamps turn OFF?

Go to Step 8

Go to Step 5

5

Test the headlamp switch signal circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs.

Did you find and repair a short to ground in the headlamp switch signal circuit?

Go to Step 9

Go to Step 7

6

Repair the short to voltage in the headlamp control circuit. Refer to Circuit Testing and to Wiring Repairs.

Did you complete the repair?

Go to Step 9

--

7

Replace the headlamp relay. Refer to Relay Replacement.

Did you complete the replacement?

Go to Step 9

--

8

Replace the headlamp switch.

Did you complete the replacement?

Go to Step 9

--

9

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2