For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
1 | Did you perform the Lighting System Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Lighting Systems
2 |

1. Turn the ignition ON, with the engine OFF.
2. Turn the headlamp switch to the HEAD position on the headlamp/instrument panel (IP) dimmer switch.
3. Pull the turn signal lever toward you in order to illuminate the LOW headlamps.
4. Turn the fog lamp switch to the ON position.

Do both front fog lamps illuminate?

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

Go to Step 3

3 | Is only one front fog lamp illuminated? | Go to Step 10 | Go to Step 4
4 |

1. Remove the fog lamp relay
2. Probe the battery voltage supply circuit of the fog lamp relay connector with a test lamp that is connected to ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 11

5 | Install a fused jumper across the battery supply voltage circuit and the fog lamps voltage supply circuit of the fog lamp relay connector. Did the fog lamps illuminate? | Go to Step 6 | Go to Step 14
6 | Probe the fog lamp relay coil supply voltage circuit of the fog lamp relay connector with a test lamp that is connected to ground. Does the test lamp illuminate? | Go to Step 7 | Go to Step 8
7 |

1. Insure that the HIGH beam headlamps are OFF.
2. Probe the headlamp high beam voltage supply circuit of the fog lamp relay connector with a test lamp that is connected to B+.

Does the test lamp illuminate?

Go to Step 15

Go to Step 12

8 |

1. Disconnect the rear window wiper/washer and multifunction switch connector C3
2. Probe the rear window wiper/washer and the multi-function switch harness connector C3 terminal D with a test lamp that is connected to a good ground.

Did the test lamp light?

Go to Step 9

Go to Step 13

9 | Test the fog lamp relay coil voltage supply circuit of the fog lamp relay for a open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 18 | Go to Step 16
10 | Test the power supply circuit and the ground circuit of the inoperative fog lamp for a open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 18 | Go to Step 17
11 | Repair the open or high resistance in the battery voltage supply circuit of the fog lamp relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 18 | --
12 | Repair the open or high resistance in the headlamp high beam voltage supply of the fog lamp relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 18 | --
13 | Repair the open or high resistance in the parklamp supply voltage circuit of the fog lamp switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 18 | --
14 | Replace the underhood accessory junction block. Refer to Relay/Fuse Center Replacement Is the repair complete? | Go to Step 18 | --
15 | Replace the fog lamp relay. Is the repair complete? | Go to Step 18 | --
16 | Replace the rear window wiper/washer and multi-function switch. Refer to Multifunction Switch Assembly Replacement - Instrument Panel . Is the repair complete? | Go to Step 18 | --
17 | Replace the inoperative front fog lamp. Refer to Front Fog Lamp Replacement . Is the repair complete? | Go to Step 18 | --
18 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2