Troubleshooting Electric Trailer Brakes that Do Not Engage with Brake Pedal

Question:

Im having a problem with my electric trailer brakes. When I unplug my brake away trailer brakes work but when I press brake on my truck the trailer brake does not work and it says on my truck that the trailer is not connected Im using my trucks oem brake controller but all the light on the trailer work. I try putting a new 7 prong cable but didnt solve the problem. 2016 Dodge Ram 3500

asked by: Serdar

Expert Reply:

Are you getting power on the pin in the 5 O'clock position on the 7-way at the rear of your 2016 Ram 3500? This is the brake output circuit. That's the first thing you need to check to find if the problem is with the truck or the trailer. If there's not power on the brake circuit the problem is likely a blown fuse.

You said you already replaced the 7-way. Was this on the truck or trailer? Whichever it was inspect the other one for corrosion and clean it if need be.

If the truck is fine then now you know the issue is on the trailer. Since the brakes work with the breakaway kit it tells me you may have something wired incorrectly. The breakaway kit needs to be spliced into the trailer's brake wire however it should not be installed inline with it. If it's inline with the brake circuit no power will get to the brakes unless the breakaway switch is triggered.

If this doesn't solve your issue let me know what you've found and we'll continue to troubleshoot.

expert reply by: Charles S