For 1990-2009 cars

## Marker Lamps Inoperative w/o super chassis w/JE4 and RQ3/U86

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: Exterior Lights Schematics
1 | Did you review the exterior lighting description and operation and perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Lighting Systems
2 | Place the headlamp switch in the PARK position. Do the marker lamps illuminate? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3
3 |

1. Place the headlamp switch in the OFF position.
2. Disconnect the lighting relay.
3. Probe the headlamp switch park lamp signal circuit of the lighting relay with a test lamp that is connected to a good ground.
4. Place the headlamp switch in the PARK position.

Does the test lamp illuminate?

Go to Step 4

Go to Step 7

4 | Connect a test lamp between the headlamp switch park lamp signal circuit of the lighting relay and the coil side ground circuit of the lighting relay. Does the test lamp illuminate? | Go to Step 5 | Go to Step 11
5 | Probe the battery positive voltage circuit of the lighting relay with a test lamp that is connected to a good ground. Does the test lamp illuminate? | Go to Step 6 | Go to Step 12
6 | Connect a 15 amp fused jumper wire between the battery positive voltage circuit of the lighting relay and the park lamp supply voltage circuit of the lighting relay. Do the marker lamps illuminate? | Go to Step 9 | Go to Step 10
7 | Test for an open, high resistance, or short to ground in the headlamp switch park lamp signal circuit of the lighting relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 15 | Go to Step 8
8 | Inspect for poor connections at the harness connector of the Headlamp 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
9 | Inspect for poor connections at the lighting 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 15 | Go to Step 14
10 | Repair an open, high resistance, or short to ground in the park lamp supply voltage circuit. 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 lighting relay coil side ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 15 | --
12 | Repair an open, high resistance, or short to ground in the battery positive voltage circuit of the lighting relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 15 | --
13 | Replace the headlamp switch. Refer to Headlamp Switch Replacement . Did you complete the replacement? | Go to Step 15 | --
14 | Replace the lighting relay. Did you complete the replacement? | Go to Step 15 | --
15 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3

## Marker Lamps Inoperative super chassis w/JE4 and RQ3/U86

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: Exterior Lights Schematics DEFINITION: Super Chassis w/JE4 and RQ3/U86, with inoperative clearance lamps.
1 | Did you review the exterior lighting description and operation and perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Lighting Systems
2 | Place the trailer marker lamps switch in the ON position. Do the clearance lamps illuminate? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3
3 |

1. Place the trailer marker lamps switch in the OFF position.
2. Remove the tractor marker lamps relay.
3. Probe the trailer marker lamps switch signal circuit of the tractor marker lamps relay with a test lamp that is connected to a good ground.
4. Place the trailer marker lamps switch in the ON position.

Does the test lamp illuminate?

Go to Step 5

Go to Step 4

4 |

1. Disconnect the trailer marker lamps switch.
2. Probe the battery positive voltage circuit of the of the trailer marker lamps switch connector with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 8

Go to Step 10

5 | Connect the test lamp between the trailer marker lamps switch signal circuit of the tractor marker lamps relay and the coil side ground circuit of the tractor marker lamps relay. Does the test lamp illuminate? | Go to Step 6 | Go to Step 11
6 | Probe the battery positive voltage circuit of the tractor marker lamps relay with a test lamp that is connected to a good ground. Does the test lamp illuminate? | Go to Step 7 | Go to Step 12
7 | Connect a 15 amp fused jumper wire between the battery positive voltage circuit of the tractor marker lamps relay and the marker lamp supply voltage circuit of the tractor marker lamps relay. Do the clearance lamps illuminate? | Go to Step 9 | Go to Step 13
8 | Inspect for poor connections at the harness connector of the trailer marker lamps 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 16 | Go to Step 14
9 | Inspect for poor connections at the tractor marker lamps 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 16 | Go to Step 15
10 | Repair an open, high resistance, or short to ground in the battery positive voltage circuit of the trailer marker lamps switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 16 | --
11 | Repair an open or high resistance in the tractor marker lamps relay coil side ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 16 | --
12 | Repair an open, high resistance, or short to ground in the battery positive voltage circuit of the tractor marker lamps relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 16 | --
13 | Repair an open or short to ground in the marker lamps supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 16 | --
14 | Replace the trailer marker lamps switch. Refer to Trailer Marker Lamp Switch Replacement . Did you complete the replacement? | Go to Step 16 | --
15 | Replace the tractor marker lamps relay. Did you complete the replacement? | Go to Step 16 | --
16 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3