Troubleshooting Left Turn Signal Not Functioning on Trailer Wiring

Question:

I have all the trailer lights working except the left brake light. Any suggestions?

asked by: Mark

Expert Reply:

Since that circuit is working as a turn signal we know it's not an issue with signal getting to the taillight, but since the brake lights draw more amperage than the left turn signal we can almost guarantee the issue is a weak ground that is preventing the circuit from being able to function. Check the condition of the ground of the left turn signal on your trailer and try improving it. If it grounds through mounting hardware make sure the attachment is clean.

I also attached a couple help articles on troubleshooting trailer wiring for you to check out as well.

expert reply by: Jameson C