Trailer Brake Controller Not Putting Out Voltage With Brake Pedal When Vehicle is Stationary

Updated 03/27/2021 | Published 03/24/2021

Question:

Tech question, I plugged in my light cord to back of pickup but did not hook pickup to trailer to activate magnets on my new brakes. They activate using controller but do not activate when pushing brake pedal, does pickup need to be fully hooked up or do I have another issue? Thanks

asked by: William A

Helpful Expert Reply:

It sounds as if you have a proportional-style brake controller. A proportional controller will only output power to the brake magnets if the vehicle is in motion. When the vehicle is stationary, you can test the trailer brakes by using the manual brake switch on your brake controller.

If you have a time-delayed type controller, voltage should be output to the trailer brakes when the tow vehicle brakes are applied. If it doesn't, you'll want to check the CHMSL (third brake lamp) fuse in the fuse box, and replace it if it's blown.

I'll link to our brake controller troubleshooting article, which you might find helpful.

expert reply by: Mike L