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For 1990-2009 cars only

Headlamps Inoperative in Low Light Conditions Pontiac, Chevy Dom, Gulf States

Step

Action

Value(s)

Yes

No

1

Did you perform the Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

  1. Cover the DRL ambient light sensor. (if applicable)
  2. Turn the ignition to the RUN position.
  3. Turn the headlamp switch to the OFF position.

Do the headlamps illuminate?

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

Go to Step 3

3

  1. Leave the DRL ambient light sensor covered(if applicable).
  2. Turn the ignition switch to the OFF position.
  3. Disconnect the DRL module connector C1.
  4. Connect a test lamp between the DRL module connector C1 terminal D (headlamps) or A (park lamps) and ground. Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

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Go to Step 4

Go to Step 10

4

Connect a fused jumper between the DRL module connector C1 terminal F (headlamp) or H (parklamp) and D (headlamp) or A (parklamp).

Do the headlamps turn on?

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Go to Step 6

Go to Step 7

5

Inspect for an open in the supply voltage circuit of the headlamp relay switch between the headlamp switch and the DRL module. Refer to Circuit Testing in Wiring Systems.

Does an open exist?

--

Go to Step 8

Go to Step 9

6

Replace the DRL module. Refer to Daytime Running Lights (DRL) Control Module Replacement .

Did you complete the replacement?

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Go to Step 12

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7

Repair a poor connection or an open in the supply voltage circuit of the headlamp dimmer switch or the supply voltage circuit of the park lamps. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Did you complete the repair?

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Go to Step 12

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8

Repair a poor connection or an open in the supply voltage circuit of the headlamp relay switch. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Did you complete the repair?

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Go to Step 12

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9

Replace the headlamp switch. Refer to Headlamp Switch Replacement .

Did you complete the replacement?

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Go to Step 12

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10

Are the inoperative lamps the headlamps and not the park lamps?

--

Go to Step 5

Go to Step 11

11

Repair a poor connection or an open in the battery positive voltage circuit of the park lamp relay. Refer to Wiring Repairs or Connector Repairs in Wiring System

Did you complete the repair?

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Go to Step 12

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12

Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 3