Trailer Brakes Lock Up with Brake Pedal on a 2007 Dodge Ram 3500

Published 09/19/2018

Question:

we own an 07 Dodge 3500 which has a brake controller installed, when we purchased the truck everything worked fine, however with 6 months we noticed the electric brakes on our horse trailer and every other trailer we have hooked up, lock up if we press the brake. It doesnt matter if you barely touch the brake or if you press it with all your might, it doesnt matter if you are rolling at an idle or if you are going 65 down the highway. We have even had our flat trailer bounce coming to stop a red light, due to the brake locking up. Also it doesnt matter if the trailers are loaded or empty. I have pulled the drums and the brakes are not rusted, no grease leaks found and there is plenty of shoe and no metal on metal wear. We need some idea of what could be the issue as we pull a trailer pretty regular and for the time we have gone to pulling the none goose-necks with our half ton dodge that doesnt have a brake controller. Any ideas? Thanks

asked by: Randy

Expert Reply:

If the trailer brakes lock up when towing with your 2007 Dodge Ram 3500 on different trailers then the issue is with the brake controller and or vehicle most likely. If the brakes lock up with the pedal then there is probably a sort on the brake output wire that runs from the brake controller all the way back to the trailer connector. If you were to test the brake output pin on the 7-way with the brake pedal depressed are you getting a full 12 volts? If so then this indicates a short in the brake output wire and you can either trace it down with a circuit tester or replace it entirely with part # 10-1-1.

The issue could also be with a short in the controller. In order to check this you will want to sever the blue wire 6" from behind the controller and test the output with a multimeter. If you get a full 12 volts with the brake pedal depressed then the issue is with the controller. If not then that indicates an error on the vehicle wiring which is listed above.

expert reply by: Conner L