Troubleshooting No Brake or Turn Signal on Trailer Right Side Tail Light

Published 09/14/2023

Products Featured in This Question

Hook Probe Circuit Tester

(66)

$14.36

16 Gauge Primary Wire - Black - Per Foot

(63)

$1.08

Deka Heat Shrink Butt Connector - 16-14 Gauge - Nylon Insulation - Blue - Qty 5

(1148)

$8.64

Question:

the lights right side of my boat trailer are not working properly. the taillights work but the brake light and turn light doesnt. the bulbs are brand new and they both light up, for some reason the brake light doesnt come on nor the turn signal. the left side works great.

asked by: Kevin N

Expert Reply:

To troubleshoot your right side brake turn signal you need to first check and make sure the ground is securely connected to a clean, bare-metal surface. If that looks good then make sure the assembly is getting 12V power by checking the wiring with a Circuit Tester # PTW2993.

Next you want to check to make sure your tow vehicle is sending power to that circuit by checking the corresponding pin to the right brake and turn signal. If all that looks good then you have some damaged wiring somewhere that you need to replace with 16 Gauge Wire # 16-1-1 and Butt Connectors # DW05744-5. The brake and turn signals are on the same circuit which is why they both aren't working at the same time.

I'm attaching a link to our wiring troubleshooting article for you to reference as well.

expert reply by: Jon G