Stock brakes locking up

[Neilbarn]

My CM stock trailer has electric brakes, a brake box and kill box. We use a 2011 GMC pickup to pull it with tow haul assist. We hooked it up last summer to haul sheep and it worked great. This week I had to pick up an emergency colic horse and after I got everything hooked up, the trailer brakes locked up when I tried to drive off. I backed up, they were still locked. To be able to use the trailer I had to unplug the electrical connection which left me without functioning lights or brakes, but the trailer wheels rolled freely then. So my brake problem has something to do with the electric part, but which part? HELP!

Neil ( a girl)

 

[tcartwri]

Look for cross tracking inside your plug and receptacle.

 

[Neilbarn]

Can I just get a new pigtail tail that is four prong and take off my 6 prong and have lights and bypass my brake system? My truck stops the trailer pretty well.

 

[ericb2400]

I had a similar problem with a horse tlr and a ford expadiaion. The truck and an rv plug the tlr had a round plug. The adapter I had hand a 12v charg wire for rv batteries but it powered the brakes on the horse tlr. changed adapters and it worked fine. Seems there are several rv to round plug adapters.

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[Neilbarn]

The trailer brakes activating themselves while I'm driving 65 is pretty scary and nerve racking, let alone panicking the horse that's in it. Would rather do without brakes then go through that again!

 

[Neilbarn]

I had a similar problem with a horse tlr and a ford expadiaion. The truck and an rv plug the tlr had a round plug. The adapter I had hand a 12v charg wire for rv batteries but it powered the brakes on the horse tlr. changed adapters and it worked fine. Seems there are several rv to round plug adapters.

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Thank You Eric! I'm on my way to try a new adapter.

 

[aczlan]

Thank You Eric! I'm on my way to try a new adapter.

Get a test light as well so that you can test how its wired and I wouldnt open the new plug until you check the wiring. There are two different ways to wire a 6 pin round plug.
In one the brakes are on the center pin and aux power is one of the outer pins (the upper left pin between 9 and 10 oclock as you look at the truck side), in the other, the aux power is on the center pin and brakes are on one of the outside pins (the upper left pin between 9 and 10 oclock as you look at the truck side).
See http://www.countrytrailer.com/uploads/6wayplug.pdf for the pinout and Viewing a thread - Trailer electrical - 6 pin round pickup to 7 pin flat trailer for someone who had a similar issue that was caused by this.

Aaron Z

 

[ericb2400]

Get a test light as well so that you can test how its wired and I wouldnt open the new plug until you check the wiring. There are two different ways to wire a 6 pin round plug.
In one the brakes are on the center pin and aux power is one of the outer pins (the upper left pin between 9 and 10 oclock as you look at the truck side), in the other, the aux power is on the center pin and brakes are on one of the outside pins (the upper left pin between 9 and 10 oclock as you look at the truck side).
See http://www.countrytrailer.com/uploads/6wayplug.pdf for the pinout and Viewing a thread - Trailer electrical - 6 pin round pickup to 7 pin flat trailer for someone who had a similar issue that was caused by this.

Aaron Z

Yes. That was exactly my problem.

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[Soundguy]

yep.. some adapters are wired with power tothe brake snad you have to swap 2 wires...

 

[Briana03]

Welcome to TractorByNet!

I moved your thread to the Trailer & Transportation forum.

 

[Diamondpilot]

If you are using the same truck are you using the same 7 pin to 6 pin adapter? Reason I ask is the converters have two styles and internally there are two wires that can be switched. Take it apart and you will see what I mean.

If yoy want to eliminate the adapter and rid yourself of the ancient 6 plug buy a new male 7 pin and wire it in directly.

Chris

 

[Soundguy]

one of these days i'm gonna do that on my old flatbed and horse trailer.. and just be 7 everywhere...

 

[RobertN]

Have hauled horses in the past.No way would I haul horses/livestock without working trailer brakes. I had to make an emergency stop with my tractor on a trailer; about the same wait as the two-horse Miley and two horses I had. I was using a borrowed flatbed trailer that was not maintained well; the brakes failed. Someone cut me off real bad and then hit the brakes; I controlled it, but it was a scary ride.

I changed out the connectors on my horse trailer and utility trailer so they matched my truck(7-wire round). Have not used adapters in a long time.

Try changing out your adapter. If that does not help, take it to a shop and get it fixed. It would be awful to have a panic stop with no trailer brakes, a couple horses in the trailer, and be out of control.

The trailer brakes activating themselves while I'm driving 65 is pretty scary and nerve racking, let alone panicking the horse that's in it. Would rather do without brakes then go through that again!

 

[Soundguy]

easy enough to check the adapter with an ohm meter and a wire diagram for a 7 pin and 6 pin. see what goes where.. without running out and buying anything.

 

[jejeosborne]

The trailer brakes activating themselves while I'm driving 65 is pretty scary and nerve racking, let alone panicking the horse that's in it. Would rather do without brakes then go through that again!

Not near as scary as driving 65 without brakes. Your tires will probably not lock up even with full gain if you have a horse in the trailer. Just correct the problem is the safest solution for all.

 

[Soundguy]

Not near as scary as driving 65 without brakes. Your tires will probably not lock up even with full gain if you have a horse in the trailer. Just correct the problem is the safest solution for all.

ditto.