Trailer brakes stop working when the headlights turn on

[chriswallace]

My Reflection has developed an issue that appears to be getting worse. On my last trip I got a Check Trailer Wiring message in my truck several times. I would stop check the connection and the message would go away. This trip before leaving home I get the message and noticed my trailer brakes were not working. After much checking and a few swear words I noticed that this only happened when my headlights were turned on. I have an observation camera so turn on headlights to turn on the camera. Since I was not planning to drive at night and under time pressure headed out. No issues first day and 500 miles. Next day I headed out for another 500 mile leg and verified again that every time I turned on my headlights, I would get the Check Trailer Wiring message and trailer brakes were not working. However, once underway I noticed that about 50% of the time I used a turn signal I would get the Check Trailer Wiring message. I assume trailer brakes were not working but as soon as turn signal turned off the message went away. I am thinking this must be a ground issue with the trailer, but not sure what to check, Any suggestions?

Chris

[jkwilson]

What truck? Some have known problems and may not apply the trailer brakes if they think the trailer isn’t connected.

[chriswallace]

2013 Chevy Silverado 2500 Duramax.

[DougW9876]

Most of the time weird things like this are due to a bad ground connection. If you have access to another trailer you could hook that up and see if the problem happens again or not and you will know if it is a truck problem or a trailer problem. Otherwise the first place to check is the connectors at the truck and the trailer. There should be a junction box where the trailer cord connects to the trailer, that is a good place to check to find the ground wire then trace it to be sure it is secure and clean at the connection point. Just keep checking wires and connections until you are sure they are all good. It is usually just a process of elimination when trouble shooting wiring on a trailer.

[Misfit]

agreed its a ground problem