Running Lights Not Working on Trailers

Question:

I have 12 Wells Cargo 24foot trailers that we use daily. On several of them the running lights have stopped working. To my knowledge the running lights do still work on several of them so I dont believe it to be an issue with the trucks. What do you think the issue could be? I havent gotten into them yet to check all the grounds so thats where Im going to start

asked by: Wesley

Expert Reply:

I would first verify that you have fully functioning connectors on all of your trucks. If it just so happens that the running light function isn't working on one of your trucks, then you could be inspecting the wiring on your trailers for nothing. You can test all of the functions using a circuit tester # PTW2993. For a 4-Pole connector it is usually the Brown wire which is right next to the ground wire. For a 7-Way connector it will be the pin in the 11 O'clock position.

If you have verified that the connectors on your trucks are all working properly then I recommend checking the connectors on your trailers for any corrosion or debris as this can cause the running lights to not work as well. Checking the grounds to make sure that they are securely connected to a clean, bare metal surface. Even some paint can cause issues.

If you have checked all of that then the next step would be to check the wiring itself for any places where the wire may have corroded, been damaged, bent, or has exposed wiring. You will want to replace it accordingly. You can use 16 Gauge Wire # 16-1-1 and Butt Connectors # DW05744-5 for replacement wiring.

If this doesn't fix your issue then let me know and I can help you troubleshoot further.

expert reply by: Jon G