Trailer Running Lights Not Working

pinebaron · Dec 17, 2024

mebsterbball said:
Just to update this Forum Thread, my issue seemed to be related to the trailer lighting control module. I replaced mine in my truck today and now my trailer running lights are working again. Thanks to everyone that jumped in here to help me diagnose and fix my issue I was having. Here are some steps I used to replace this module.

Thanks!

Dbart71 · Apr 13, 2026

I am having issues with my trailer in that it says issue with Left blinker not working, brake lights not working...then I get the notification that trailer has been disconnected, check connection. I bought a 7-pin plug in tester to go into my trucks 7-pin and there is an issue with the unit on my truck. I took this same tester and plugged into my brother's truck and shows all is working fine. Good thing for a warranty, time to call the dealer!
I'll see what they say...
Oh for those interested, this is what I bought to test my truck.

https://www.amazon.com/dp/B0DR8KYPNQ?ref=ppx_yo2ov_dt_b_fed_asin_title

pinebaron · Apr 14, 2026

Dbart71 said:
I am having issues with my trailer in that it says issue with Left blinker not working, brake lights not working...then I get the notification that trailer has been disconnected, check connection. I bought a 7-pin plug in tester to go into my trucks 7-pin and there is an issue with the unit on my truck. I took this same tester and plugged into my brother's truck and shows all is working fine. Good thing for a warranty, time to call the dealer!
I'll see what they say...
Oh for those interested, this is what I bought to test my truck.

https://www.amazon.com/dp/B0DR8KYPNQ?ref=ppx_yo2ov_dt_b_fed_asin_title
View attachment 36815

Thats cool !