Troubleshooting LED Trailer Lights Not Functioning Consistantly

Question:

I recently bought a used trailer with led tail lights. Its a very light tear and I will tow it with my 2012 subaru impreza. But the electrical is intermittent. Sometimes all tail lights illuminate fine, but sometimes not, or they blink. Will load resistors fix this?

asked by: Karen B

Expert Reply:

For your light tear trailer the LED lights could be the issue requiring a load resistor to draw more power than the LED for correct function, but we don't have enough information to confirm since at times they work fine, or not at all, while at other times they blink. It sounds more like a short in your wiring or a bad ground connection. Normally if it were just the need for load resistors you would have the blinking but they would always still have power. It really sounds like a bad ground to your trailer where there isn't a solid metal to metal connection. You will want to check the ground at your vehicle side wiring harness, then at your main trailer ground to the frame and at each tail light as they often have a ground there as well.

If that doesn't solve your issue, then I recommend testing your wiring using a circuit tester like # PTW2993 to probe your wires every few feet.

expert reply by: Jason S