For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics
1 | Did you review the headlamps description and operation and perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Lighting Systems
2 | Place the headlamp switch in the HEADLAMP position. Do the low beam headlamps illuminate? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3
3 |

1. Turn ON the ignition, with the engine OFF.
2. Place the headlamp switch in the OFF position.
3. Disengage the parking brake.

Are the daytime running lamps (DRL) ON?

Go to Step 4

Go to Daytime Running Lamps (DRL) Inoperative

4 |

1. Turn OFF the ignition.
2. Remove the DRL relay.
3. Probe the headlamp dimmer switch headlamp low beam supply voltage circuit at the DRL relay with a test lamp that is connected to a good ground.
4. Place the headlamp switch in the HEADLAMP position.
5. Place the headlamp dimmer switch in the LOW position.

Does the test lamp illuminate?

Go to Step 6

Go to Step 5

5 |

1. Place the headlamp switch in the OFF position.
2. Disconnect the headlamp dimmer switch.
3. With the test lamp still connected, connect a 40 amp fused jumper wire between the headlamp switch signal circuit of the headlamp dimmer switch and the headlamp low beam supply voltage circuit of the headlamp dimmer switch.

Does the test lamp illuminate?

Go to Step 7

Go to Step 8

6 | Inspect for poor connections at the DRL relay. 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 11 | Go to Step 9
7 | Inspect for poor connections at the harness connector of the headlamp dimmer 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 11 | Go to Step 10
8 | Repair an open, high resistance, or short to ground in the headlamp low beam supply voltage circuit. Refer to Circuit Testing or Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 11 | --
9 | Replace the DRL relay. Did you complete the replacement? | Go to Step 11 | --
10 | Replace the headlamp dimmer switch. Refer to Turn Signal Multifunction Switch Replacement in Steering Wheel and Column. Did you complete the replacement? | Go to Step 11 | --
11 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3