Electric Trailer Brake Woes

[adventureduo]

We have electric brakes on our Horizon and after i took it through a water crossing this past weekend the brakes haven't worked right since. Come to think of it i may have tapped the brakes for a short second while in the crossing. I've been told that there's no real way of hurting them doing this because the magnets should be sealed.. but i think otherwise. Further down the trail i was getting weird readings on my brake controller. It was turned to ZERO and it would read voltage even though i had to it turned down. Once returning back to civilization i noticed even at full voltage the trailer would do hardly anything.

Any thoughts on what's going on? Haven't had a chance to look at the brakes yet as im headed back out on another trip. Seems like something got gunked up and needs attention.

 

[red_5]

Don't know if you've tried this already as quick test:

Engage your breakaway switch and check the trailer brakes. If the breakaway battery is up the brakes *should* be fully engaged.

If the brakes don't engage fully, then you've got a problem on the trailer side.

If they do, then it's likely a vehicle side problem or the connector is wonky.

Water could conduct some of your braking power right to ground if the wiring gets wet and creates a path of lower resistance.


If water was an issue, I'd expect it to go away once things dried out though.

 

[elmo_4_vt]

While that can help diagnose a problem, MAKE SURE YOU DISCONNECT THE CAR before you try the break-away switch. If not, it can back feed and if you have a prodigy, it will short it. Expensive mistake.

 

[Martyn]

Dave

Start out by checking the brakes by pulling the pin out of your brake away and then trying to roll the trailer forward. The brakes should engage within a 1/4 turn.

Keep me posted on the results.

 

[adventureduo]

Ok, yanked the E-brake on the trailer. Works fine. That doesn't mean there's not a short on the trailer still.

 

[Martyn]

Ok, yanked the E-brake on the trailer. Works fine. That doesn't mean there's not a short on the trailer still.

That's correct it doesn't mean their isn't a short on the trailer, but it's pointing a finger directly at the vehicle side. You need to test the brakes at the vehicle socket to make sure they are working, and then take a long hard look at your controller.

 

[red_5]

Checking the negative leads wouldn't hurt either. Particularly between the vehicle and trailer. Bad grounds can cause all kinds of mayhem.

While that can help diagnose a problem, MAKE SURE YOU DISCONNECT THE CAR before you try the break-away switch. If not, it can back feed and if you have a prodigy, it will short it. Expensive mistake.

:Wow1:

That's something I was not aware of. You'd think that since break away devices are mandatory (at least where I'm at) there'd be some kind of protection against that sort of thing built in.

 

[elmo_4_vt]

That's something I was not aware of. You'd think that since break away devices are mandatory (at least where I'm at) there'd be some kind of protection against that sort of thing built in.

I know what you mean about expecting built in protection, but there were statements in both my Prodigy brake controller manual and the Break away module manual.

 

[adventureduo]

Ok, truck is 100% right on the money. My buddy at Miracle Muffler and Trailer Hitch plugged in a system that tests the entire brake/lighting. Everything checked out. I need to look at the trailer now. Heck, the thought crossed my mind that it may even need new brakes. It's Mario's old trailer and it's never had a brake job done by us (we've put at least 15-20k on it). I'll tear it apart and inspect next week. It may be time for new brakes.

 

[Martyn]

Ok, truck is 100% right on the money. My buddy at Miracle Muffler and Trailer Hitch plugged in a system that tests the entire brake/lighting. Everything checked out. I need to look at the trailer now. Heck, the thought crossed my mind that it may even need new brakes. It's Mario's old trailer and it's never had a brake job done by us (we've put at least 15-20k on it). I'll tear it apart and inspect next week. It may be time for new brakes.

Dave.

If the truck checks out fine, and the brakes work between the breakaway and the drums, I'd look at the connection between the plug and the junction box.

A few possibilities, If you have a plug that is removable i.e. not a sealed unit to the cable, a wire may have come loose. Or the wire to the brake terminal in the junction box may be loose. It's the blue wire on the far right looking from the back of the trailer. Last possibility is that there may be something wrong with the cable. We have experience that once with a sealed unit.

In summary look for:
Defective plug
Defective cable
Loose connection to blue terminal in Junction box.

While you are in the junction box check that all your grounds are tight on the terminal to the far left, and the jumper cable from that terminal has a good grounding to the chassis via the bolt that holds the junction box in place.

 

[adventureduo]

Well, all the testing is complete and i couldn't really find anything wrong.

So i took it into my trailer guy. They pulled the drums and found that the magnets aren't pulling hardly anything. No strength left in them (barely pulls a screw driver towards em). That and somehow someway the wiring was melted causing a short and the pads are at about 50%. So all new brakes are going with new seals. Better safe than sorry.

Weird, but at least i know it will be good to go now.