Troubleshooting Left Turn Signal and Brake Light Not Working After 7-way Adapter Installation

Question:

I just installed the 7 blade round on my Jeep Wrangler. I am unable to to get my left turn signal and brake light to function. I have checked continuity on the harness and only have continuity on black wire,red wire, and blue wire. I have power to all trailer lights, other than the left turn signal and brake light. Could it be a bad ground?

asked by: Bill M

Expert Reply:

To answer your question, yes, it could be a bad ground. I would double check the ground from your 4-way as well as the ground for the 7-way adapter. Make sure they are securely attached to a clean, bare metal surface. You may even consider moving the ground from the recently installed adapter to a new position. The ground wire on the # C57672 should be secured directly to the frame.

If that doesn't fix it, I would check all of the connections related to the left turn signal and make sure they are secure. You could also use a circuit tester like # PTW2993 to check the left turn signal wire and narrow down where the problem is. Start by testing at the 4-way plug, if that does not work, test the wiring going into the converter box from the vehicle side. Typically if one function does not have the correct power reading the connectors are not secure or there is a loose wire behind the connector.

I have attached a helpful article on troubleshooting wiring for your reference. If you are unable to find and fix the problem please reach out and I will help you troubleshoot further.

expert reply by: Robin H