For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: Exterior Lights Schematics DEFINITION: Super Chassis w/JE4 and RQ3/U86, with the clearance lamps always ON.
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 OFF position. Are the clearance lamps OFF? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3
3 | Remove the tractor marker lamps relay. Are the marker lamps OFF? | Go to Step 4 | Go to Step 8
4 | 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. Does the test lamp illuminate? | Go to Step 5 | Go to Step 6
5 |

1. Leave the test lamp connected.
2. Disconnect the trailer marker lamps switch.

Is the test lamp OFF?

Go to Step 7

Go to Step 9

6 | 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 12 | Go to Step 10
7 | 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 12 | Go to Step 11
8 | Repair a short to voltage in the park lamp supply 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 12 | --
9 | Repair a short to voltage in the trailer marker lamps switch signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 12 | --
10 | Replace the tractor marker lamps relay. Did you complete the replacement? | Go to Step 12 | --
11 | Replace the trailer marker lamps switch. Refer to Trailer Marker Lamp Switch Replacement . Did you complete the replacement? | Go to Step 12 | --
12 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3