Troubleshooting Brake and Turn Signal Not Working on Trailer Hooked up to 2013 Yukon

Question:

Hi, I have a 2013 GMC Yukon hooked up to a Aistream trailer. The diver side rear brake/turn signal does not work on the trailer when hooked up to the Yukon. I also have the same Tekonsha brake controller on my Toyota Tacoma and the light on the trailer works fine when hooked up to the Toyota, so seems something is wrong with the connection from the Yukon. Before I start troubleshooting to much I wanted to see if there is a certain connection to check or something simple that might be wrong with the Yukon. Have any advice or need anymore details? Thanks

asked by: Fran R

Expert Reply:

The fact that the trailer works fine on your Tacoma is good news because that allows you to rule out the possibility that the issue is on the trailer and allows you to focus on the connections with your Yukon. Just disconnect the plug from your trailer and use a circuit tester to see if the signals are getting to your plug. You will also want to check location 3 in the fuse panel under the hood, which is the left trailer stop and turn lamp fuse.

If they are it might also be corrosion in your Yukon's connector. A build-up of corrosion can interfere with the signals getting through the connectors so if it is present you will need to either replace the plug or clean the corrosion and be sure to use Dielectric Grease # LT37534 in the future to help stop any future corrosion.

expert reply by: Kyle S