Troubleshooting Trailer Tail Lights Not Working When 2020 Blazer Headlights Are Turned On

Question:

Hello, I bought a cutis 4 prong trailer harness from you. For 2020 Chevrolet Blazer. And it was easy install, but having issue with lights on trailer, they work fine when vehicle light position is in Auto but when gets dark and vehicle headlights come on trailer lights go out. Also when move vehicle lights off auto, to parking or full headlights trailer lights stop working. Any suggestions? Fuses good and replaced lights on trailer. Same issue. Thanks

asked by: Joel B

Expert Reply:

First I recommend testing the 4-way on a different trailer otherwise you could use a Tester # I26 or Test Light # PTW2993 to verify the issue is not with the Curt 4-Way # C56325 or your 2020 Chevrolet Blazer.

If you have verified the issue does not repeat itself on another trailer or with a tester then the issue is most likely related to a ground issue. It may be the ground connection from the trailer to the trailers 4-way is not making good contact and is causing your issue.

Please check these things and let me know what you find and I can further help you to determine other possible issues.

expert reply by: Bud M

Joel

3/6/2024

Thanks, I just see this response. I appreciate your time and response. I found bad ground wire. Ran new ground on trailer and all is well. Thanks again