Anone understand elec trailer brakes?

Whitnel · Jul 8, 2011

I would replace your trailer plug and truck plug before buying a new brake controler or at least clean them. I had a problem with no trailer brakes once. Figured the controler had went bad and got a new one. Replace the controler and still no brakes. I then started testing. Had power at the brake wire before the truck plug but not at the plug itself. Turns out the terminal inside the truck hook up had rusted in two. Replaced the guts and everything was good.

crazyal · Jul 8, 2011

If it was just in reverse then I would say it could be a ground issue. If you had a bad ground when you send power to turn on the reverse lights and there's a bad ground path the power will try to find a path to ground. It's possible that it's going through the electro magnets and going back to the controller and finding a path to ground. But I would think that would mean you have to have reverse lights on the trailer.

Which controller did you end up with? Did you ever check to see if you have reverse light wired up to your 7 pin trailer plug? If so I would still try to remove it from the circuit, either pull the fuse (if it's on it's own) or remoove the wire from the plug. Just a sanity check.

sixdogs · Jul 10, 2011

This is the brake controller I ordered.

Amazon.com: Reese Towpower 74643 Brakeman Digital Brake Control: Automotive

Since I already have one I picked it for ease of installation and mostly 5 star ratings. Plus, It's only $35. Remember too, I only use this trailer a couple times a year.

It sure could be a bad ground or a bad plug but the trailer has never even been wet and sits in a dry barn. Same for the truck. Those two cause most problems but I'm going to gamble on the unit. Plus, to search for all the other potentials is so much grief that a $35 gamble is worth it.
The unit ought to get here Wed or Thursday of this week so I'll update when I know more.

sixdogs · Jul 18, 2011

Still waiting on the part.
Will advse when it gets here and I test it.

radioman · Jul 18, 2011

I had a similar problem. my trailer would either lock up too much or no braking power when messing around with gain. it turned out to be a on inch section of melted brake power wire that corroded over the years on my truck. how it happened in that spot, i'll never know. I cut that section out and soldered it back together and it been fine for a few years still.

tpic402 · Jul 18, 2011

Which trailer plug r you using rv,flat,, 6 pole, test for bad grds with test light or volt meter, you will see voltage on grd side through light or meter if you have a bad grnd, is the trailer plug plugged in properly check female indent mates up with male ridge if understand what i mean, you can find proper trailer harness wiring on internet, Have never seen contoller cause locking up in reverse mainly because most applications do not use reverse lights on trailer, more than likely it is a rust thing.

sixdogs · Jul 18, 2011

I have a 7 pin connector and will scrub up ground and contacts.
It's time for me to upgrade the brake controller anyway so we'll see.

sixdogs · Jul 19, 2011

I sort of hate to type this but the problem was a loose wire in the trailer part of the 7 pin connector that apparently damaged the brake controller and caused it to intermittingly work by surging voltage. But the the story really began 12 years ago when I first wired the trailer plug connector.
Being short one wire end eyelet, I just shoved the wire under the clamp/screw thing and said to myself, with an air of confidence, "I'll take care of that tomorrow". Yeah, right.
Well today was "tomorrow" and that clamp loosened and the wire touched some other things. That's my story and the problem was my incomplete installation. There's a moral there somewhere.

On the plus side, I do like my new $36 brake controller and it is nice to actually see the voltage being applied to the brakes. It's hard to beat that price for occasional use. Everything is now OK and no more digging up the gravel in the driveway. Wife happy, dogs happy and the brakes work again. Case closed and thanks to all TBNers that helped. I am right now searching for a celibratory "Rolling Rock" as we speak.