Troubleshooting Trailer Turn/Stop Signals Not Working

Question:

What could be the problem with the turning signals on left and right and brake lights on bith

asked by: Jeffrey

Expert Reply:

There are a number of things to check when troubleshooting the left turn/stop and right turn/stop signals not working on your trailer. The first places to start are the connectors on both your tow vehicle and your trailer. Make sure that both are clean and free of any debris or corrosion. If you find something then clean it out and apply dielectric grease # 11755 to help keep the pins in good working order.

If those look good then the next step is to determine if the signal is actually getting to your tow vehicle connector. Use a tester like part # PTW2991 to make sure both circuits are working properly (see attached photos for pin placement). If they aren't working properly then you may need to replace some fuses or relays. If they are working properly then you need to move on to your trailer.

On your trailer side look for any grounds that are damaged and make sure they are securely connected to a clean bare-metal surface (whether the ground is through a wire or the mounting hardware). Also check your stop/turn circuits to make sure that all of your wiring is in good working order and replace any parts that are damaged, exposed, or bent.

Attached is a helpful article on wiring troubleshooting. If you continue to have problems just let me know and I can help you troubleshoot further.

expert reply by: Jon G