Anone understand elec trailer brakes?

[crazyal]

Is it just one wheel locking up or both (or all four if it's a two axle trailer with brakes on both axles)? If only one wheel is locking up then I would suspect the wheel, if all four then the truck side.

Most likely isn't a ground since the way the brakes work (at least all the ones I've worked on) is the brake shoe is connected to a lever. On the other end of the lever is an electro magnet. As electricity is applied to the magnet it grabs the side of the drum. The higher the voltage the stronger the magnetic force the more friction it creates against the drum and in turn the more force it applies to the brake shoe. A bad ground would reduce, not increase the force. It could be possible that the brake controller's ground is bad but they usually are inside the truck in a place that doesn't corrode.

You still may want to pull off a drum and take a look inside. To remove most trailer brake drums you have to pull the cap over the bearings off and remove the large nut that puts tension on the bearings. It's a good time to service the bearings and replace the seal. If you're unsure how to do it ask and I'm sure plenty here can guide you trough it.

I have one of the more advanced brake units. I think it's made by Tekonsha, Prodigy maybe. I'll never go back to the more basic units again. No more jerky trailer while in stop and go traffic, no more brakes being applied while backing up, no more wheels locking up because the trailer is unloaded, it just works great. I even think they make a higher level controller.

 

[sixdogs]

Remember, this worked fine for six years. If not wired correctly it would have quit a long time ago. All four wheels lock up and only in reverse and they lock up as soon as I put it in "R".
The trailer has never been driven in the rain and the truck has only 25,000 miles and sits in a dry barn.
Seems to me it has to be the control module and I'm thinking to get one of the Tekonsha units and call it good.
After all, there are some pretty smart guys here and if none of you have a good idea it's time for me to start replacing things. I'm as stumpede as everyone else.

 

[jbos333]

I install brake controllers and hitches for a living. There seems to be 2 seperate problesms here....a. Brakes are touchy/locking up going forward - I'm assuming trailer is empty/unloaded? This is pretty common and could be due to some moisture/light rust in the drums. Does it act differently when loaded? b. Brakes lock up completely in reverse. As someone else may have mentioned, this is a feature on some trailers. Your old truck may have had this wire hooked up to the 7 pin harness, and your new truck may not. It's just hooked up to the reverse light circuit to release the brakes. It has nothing to do with your brake controller at all.

Hope this helps!

Oops! I went back and realized it's the same truck and trailer (I think). If so, is your reverse light circuit still giving 12V when in reverse? Maybe a blown fuse or corrosion on the 7 pin setup?

 

[sixdogs]

Everything works fine going forward. There is no rust anywhere--that I am aware of-- since the trailer is not used much and sits in ideal indoor conditions. The truck is rarely used as well and has not even been in the rain for a couple years.
The only problem is when I shift into reverse. All for wheels lock up immediately. No stick or touchy--just lock up.
I'm going to go out in a while and hook up again and try some other options of playing with the sync and control buttons. Thank you

 

[Skyco]

That is a weird one....I've had a bunch of trailers with electric brakes and usually they don't work very well at all in reverse, let alone lock up!
Always worried me if I had to back down a steep hill.


Nobody sneaked in and turned your axles around?:confused3:

 

[crazyal]

Do you know if the reverse lights are wired up to your 7 pin trailer plug? If so maybe the reverse wire is sending power to the trailer brakes. Maybe you could pull the fuse for the reverse lights and see if the problem goes away.

 

[Egon]

Maybe pull a hub off and check out the internals.

 

[sixdogs]

I just spent two (more) hours on this and figured it out. Well, maybe not figured it out but it works and I'm not sure I understand why.
There is no question all four wheels locked up in reverse and in reverse only. We tried everything, including disconnecting and reconnecting and no dice. I've got two days in this.

Then we found on the internet for the older---2005-- Reese unit that the output control MUST be set first and then the sync control second. Since we had done everything else we tried that and still no dice. Then we disconnected the trailer again and THEN moved the output control and then the sync control second.
Hooked everything up and it worked. Buzzed around the yard and we could not get the brakes to lock up no matter what.

I have no idea what happened and not sure if it will work tomorrow but that sequence stopped the lockup. I'll unhook and hook up again and see what happens but I am blaming the unit and some sort of internal problem. There is no other option.
The trailer was 100% wired right and everything is in showroom condition. What else? Remember it worked fine for six years.
This is the worst outcome since now I don't know exactly what happened and don't have a definitive answer. Maybe I should change the brake unit just for the heck of it?
Beats me but wish me luck the next time I get to 70 MPH with the trailer. Thanks to all and let's hope this helps someone in the future.

 

[Egon]

It was the "Gremlins".

Glad you got it figured out.:thumbsup:

 

[DRL]

I have one of the more advanced brake units. I think it's made by Tekonsha, Prodigy maybe. I'll never go back to the more basic units again. No more jerky trailer while in stop and go traffic, no more brakes being applied while backing up, no more wheels locking up because the trailer is unloaded, it just works great. I even think they make a higher level controller.

I agree. I also have the Prodigy, best controller I have ever messed with.

DRL