Question Was Asked By - Mitch

Left Taillight Not Functioning on Trailer

Question:

I can get right side to light up and the side marker on the left, but not the left tail light. I have tried different wires and a different tail light. Im stymied.

asked by: Mitch

Expert Reply:

Your first step is to determine whether the problem is with the vehicle or the trailer. Use a circuit tester, such as part # 40376 and check your trailer connector on the vehicle as each function is activated. If this all checks out, then the problem is with the trailer wiring. Start at the point where the trailer and vehicle wiring connect. Examine each side of the connector for damage or corrosion. The yellow wire carries the left directional/brake light circuit, trace this circuit all the way back to the fixture, looking for pinched or broken wires. Examine the wire insulation for cracks or spots where the insulation has been worn off. If the copper conductor has been exposed and is making contact with the trailer frame, the circuit can short out to ground. Finally, you will want to make sure the grounding point on the trailer tongue is securely fastened and not corroded.

expert reply by: Mike L

Products Referenced in This Question

Circuit Tester Kit