Trailer brakes locking when going in reverse?

[2_wacko]

My truck drives fine everywhere but when I go in reverse the trailer brakes lock up? What could be causing this?

 

[throttleissues]

If they're surge brakes, that means they're working properly. In that case, SOME brake assemblies have a lockout lever for backing up. If they're electric, then I'm guessing maybe your backup lights are wired into the trailer plug and powering your trailer brakes. You didn't give much info, but I hope one of those explains the problem.

 

[454k30]

I've seen plugs get installed like that, with the reverse light powering the trailer brakes. It would help a lot to know what type of setup you have though.

 

[2_wacko]

Its a 1987 1/2 ton 4x4 the plug in has 5 or 6 holes that plug into the truck harness. The trailer is a 18 foot car hauler.

 

[moneypit_K5]

you didnt mention whether it had surge brakes or not.

If it doesn't, then i would find which port on the truck plug is the brake power and see if its getting power when it is in reverse gear. (just turn the key on, engine off, the tires blocked). if all is good there, then it must be in the trailer wiring.

 

[2_wacko]

How can I tell if it has surge brakes?

 

[moneypit_K5]

surge brakes are a system that is built in to the tongue of the trailer.

when you slow down, the momentum of the trailer compresses the tongue, and the trailer brakes.

conversely, if you were to back up suddenly, or back up a hill, you vehicle would compress the tongue into the trailer, causing the brakes to engage.

 

[2_wacko]

No surge brakes, when hooked up to my 2005 dually the brakes lock going forward not in reverse its the other way around. On my 87 they lock in reverse wtf?

 

[moneypit_K5]

check your post replys

If it doesn't(have surge brakes), then i would find which port on the truck plug is the brake power and see if its getting power when it is in reverse gear. (just turn the key on, engine off, the tires blocked). if all is good there, then it must be in the trailer wiring.

If they're electric, then I'm guessing maybe your backup lights are wired into the trailer plug and powering your trailer brakes. You didn't give much info, but I hope one of those explains the problem.

I've seen plugs get installed like that, with the reverse light powering the trailer brakes. .