Troubleshooting Trailer Lights Only Working on One Side

Updated 08/20/2019 | Published 08/19/2019

Products Featured in This Question

Hopkins Endurance Easy-Pull Y-Harness with 4-Pole Flat Trailer Connector - Trailer End - 20'

(13)

$25.89

LCD Digital Circuit Tester

(26)

$26.67

Question:

I am building my own tear drop and had to wire in a license plate light. I used the passenger side tail light to feed the license plate light. All the lights illuminate, but the tail light blinker and brake light wont work. What did I do wrong?

asked by: Stacy

Expert Reply:

You need to first check all of your lighting connections if all of your lighting functions aren't working on one side and you used a y-harness like the Hopkins # HM48244 then you need to check the wiring directly from the 4-Way for that side of your trailer. Hook up the trailer connector to your vehicle and then use a circuit tester like part # PTW2992 to see where the signal stops on that side. It will also help to check all of your lighting grounds on that side as well.

I have attached a link to our helpful article on troubleshooting trailer wiring but if you are still having issues let me know and I can help you troubleshoot further.

expert reply by: Jon G