GM Service Manual Online
For 1990-2009 cars only

Headlamps Inoperative - High Beams Domestic

Step

Action

Yes

No

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

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

DEFINITION: The high beam headlamps are inoperative, low beam headlamps operate properly.

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. Turn the headlamp dimmer switch to the HIGH position.

Do the high beam headlamps operate properly?

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

Go to Step 3

3

Are both high beam headlamps inoperative?

Go to Step 4

Go to Step 6

4

Using a test lamp connected to ground, probe the high beam supply voltage circuit of connector C201.

Does the test lamp illuminate?

Go to Step 5

Go to Step 9

5

Backprobe the high beam supply voltage circuit of the underhood junction block connector with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 10

Go to Step 11

6

Using a test lamp connected to ground, probe the high beam supply voltage circuit of the inoperative headlamp.

Does the test lamp illuminate?

Go to Step 8

Go to Step 7

7

Test for an open or high resistance in the supply voltage circuit of the inoperative high beam headlamp. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 10

8

Inspect for poor connections at the harness connector of the inoperative headlamp. 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 15

Go to Step 12

9

Inspect for poor connections at the harness connector of the turn signal 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 15

Go to Step 13

10

Inspect for poor connections at the harness connector of the underhood junction block. 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 15

Go to Step 14

11

Repair an open, high resistance or a short to ground in the high beam supply voltage circuit of the underhood junction block. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 15

--

12

Replace the inoperative headlamp. Refer to Headlamp Assembly or Headlamp Bulb Replacement .

Did you complete the repair?

Go to Step 15

--

13

Replace the turn signal switch. Refer to Turn Signal Multifunction Switch Replacement in Steering Wheel and Column.

Did you complete the repair?

Go to Step 15

--

14

Replace the underhood junction block. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems.

Did you complete the repair?

Go to Step 15

--

15

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2

Headlamps Inoperative - High Beams Export

Step

Action

Yes

No

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

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

DEFINITION: The high beam headlamps are inoperative, low beam headlamps operate properly.

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. Place the headlamp switch in the HEAD position.
  3. Place the headlamp dimmer switch in the HIGH position.

Do the high beam headlamps operate properly?

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

Go to Step 3

3

Are both high beam headlamps inoperative?

Go to Step 5

Go to Step 4

4

Inspect the corresponding fuse of the inoperative high beam headlamp for an open.

Is the RH or LH HEAD LP high fuse open?

Go to Step 12

Go to Step 7

5

Place the headlamp dimmer switch in the flash-to-pass position.

Does the flash-to-pass feature operate?

Go to Step 9

Go to Step 6

6

  1. Place the headlamp dimmer switch in the HIGH position.
  2. Using a test lamp connected to ground, probe the headlamp high beam supply voltage circuit of connector C201.

Does the test lamp illuminate?

Go to Step 10

Go to Step 9

7

Using a test lamp connected to ground, probe the high beam supply voltage circuit of the inoperative headlamp.

Does the test lamp illuminate?

Go to Step 8

Go to Step 11

8

Inspect for poor connections at the harness connector of the inoperative headlamp. 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 15

Go to Step 13

9

Inspect for poor connections at the harness connector of the turn signal 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 15

Go to Step 14

10

Repair an open or high resistance in the high beam supply voltage circuit of the headlamp switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 15

--

11

Repair an open or high resistance in the supply voltage circuit of the inoperative high beam headlamp. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 15

--

12

Repair a short to ground in the high beam supply voltage circuit of the inoperative headlamp. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 15

--

13

Replace the inoperative headlamp. Refer to Headlamp Assembly or Headlamp Bulb Replacement .

Did you complete the repair?

Go to Step 15

--

14

Replace the turn signal switch. Refer to Turn Signal Multifunction Switch Replacement in Steering Wheel and Column.

Did you complete the repair?

Go to Step 15

--

15

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2