Troubleshooting A Right Brake Light That Stays On Even After The Trailer Is Unplugged

Question:

My 2 year old camper that was used this past weekend now has the right break light staying on when unplugged from tow vehicle. I have checked what I can by tracing wires from light to battery, no issues that I can see, no exposed wires or loose grounds, nothing dirty or corroded. I did notice that the break light was half full of water when I removed it. I plan to take the camper in to a professional, I expect it will be weeks or months before they will have time to get the camper repaired. I have several trips booked in the next month or so. Would it be safe to use in this condition? The right break light wiring is located under the bunk beds that will be full of kids. I hate to think of the possibility if something would happen to cause a fire from this issue. What are your thoughts?

asked by: Matt H

Expert Reply:

This is usually caused by the trailer battery reaching the right brake and turn signal circuit, however this circuit should not be connected to the trailer battery.

The first thing you can do is check the wire connections inside the of your trailer connectors. On your 7-way, your 12v power wire is located right next to your right turn and brake signal, and if these wires happen to be touching then that would explain why your right brake light is constantly receiving power.

Additionally, water inside your brake light housing is not super common, however it does happen and it should be addressed sooner than later as the water can prematurely corrode parts of your electrical system.

I have attached a FAQ that goes into detail about some more troubleshooting you can do as well.

expert reply by: Bryce D