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

Did you review the headlamp description and operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Lighting Systems

1. Place the headlamp switch in the HEADLAMP position.
2. Place the headlamp dimmer switch in the LOW position.

Do the low beam headlamps illuminate?

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

Go to Step 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 in Symptoms

1. Turn OFF the ignition.
2. Remove the DRL relay.
3. Probe the headlamp low beam supply voltage circuit of the headlamp dimmer switch 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

1. Place the headlamp switch in the OFF position.
2. Disconnect the headlamp dimmer switch.
3. With the test lamp still connected, connect a 30 amp fused jumper wire between the headlamp switch signal circuit and the headlamp low beam supply voltage circuit.

Does the test lamp illuminate?

Go to Step 7

Go to Step 8

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

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

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

--

Replace the DRL relay. Refer to Daytime Running Lamps (DRL) Relay Replacement .

Did you complete the replacement?

Go to Step 11

--

Replace the headlamp dimmer switch. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle in Steering Wheel and Column-Standard.

Did you complete the replacement?

Go to Step 11

--

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3