Left Side Trailer Tail Lights and Blinkers on a Kaufman 43 ft Car Hauler Won't Work

Updated 07/23/2024 | Published 09/23/2019

Products Featured in This Question

Peterson Trailer Tail Light w/ Grommet and Plug - Stop, Turn, Tail - Incandescent - Round - Red Lens

(1163)

$15.85

LCD Digital Circuit Tester

(28)

$28.06

Question:

Why is it that I only have right turn signal right brake lights and right flashers on my trailer all my lights are working except for the turn signal brake light and flashes on the left side of my trailer

asked by: Joseph B

Expert Reply:

I've got a couple troubleshooting steps you can go through to determine the cause of this, but it sounds like the right side of the trailer is fully functional and the left side isn't. You can start by testing your vehicle's wiring harness. First check and make sure that the harness is free from dirt and debris; clean it off as needed. Next, you'll want to use a circuit tester like # PTW2992 to make sure that all of the pins on the vehicle harness are delivering power as they should. I've attached a picture of a vehicle 7 way connector as well as our help article on wiring which has the 4 way chart, so you can verify which pins deliver which functions while doing this. If there is a pin that isn't delivering power, the wire running behind this pin is going to be where the error is occurring if the vehicle harness is the culprit- if your vehicle lights are functioning properly, just trace back from the harness to where it plugs into the lights to find the damaged wire.

If you're getting power to the vehicle harness fully, check for a faulty ground wire on the trailer. Check the ground wire and make sure that it is securely connected to a paint and debris free surface. Next you'll need to trace the wires to the lights on the lefthand side of the trailer from the harness to the lights checking for damaged wires-replace any damaged wires as needed and reconnect any lights that may have gotten disconnected.

If these steps haven't resolved your issues, please let me know and I will give you a couple of other steps to continue the process.

expert reply by: Erik B