Troubleshooting Brake Lights On Trailer Not Illuminating

Question:

when I hook up my rv trailer,all lights work except brake lights when pedal is pushed

asked by: William D

Expert Reply:

The first thing to check is the trailer connector on the vehicle to make sure the pins are free of corrosion and dirt. You want to make sure all of the connections are seated properly, and you there are not any bent or broken pins. You also want to check to make sure the ground on your trailer connector is grounded to a clean bare metal surface.

If you all of your pins and the ground is okay, you want to make sure you are getting power to the left turn/stop and right turn/stop pins on the connector. You can test this with a circuit tester like part #PTW2993. I have attached a photo that shows the standard pin configuration of a vehicle side 7-way connector. If you are getting power here the issue most likely is on the trailer side wiring.

You want to check the left turn/stop and right turn/stop wire back to the trailer for damage or frayed wire. You also want to make sure the trailer wiring connector is grounded properly.

If you are not getting power to the trailer connector on the vehicle then the issue is on the vehicle's side. You may need to check the wiring on the trailer connector for damaged or frayed wire. If your vehicle has a towing package you may be missing a fuse or relay. You may also have a factory tow package plug in port where your vehicle's 7-way plugs into. You want to check that the 7-way is fully seated into that port as well.

expert reply by: Heather A