Bypass breakaway to narrow down electric break issue?

[petebert]

I'm trying both the brake controller that came used and already installed on my truck(activator II) and I replaced all the electric brakes on a trailer I've never used before. So far the brakes aren't working and I'm trying to narrow down the issue. I've never used the brake controller on this truck, so right now I'm not sure if the issue is truck side or trailer side.

I haven't tested the wires at the back of the controller yet. So far all I get on it is a single dot which means the controller thinks there isn't a trailer attached. I've double checked the harness wiring and it is correct. Everything on the trailer works except the brakes.

Can I bypass the breakaway and just go blue/blue ground/ground all the way to harness to eliminate that as an issue?

I'm not finding any grounds actually attached to the trailer. Looks like the previous owners just ran it off vehicle ground, could this be an issue? This is an equipment trailer that was left by the previous owners of my house and included in the closing. The brakes shoes were worn down to bare metal so I'm assuming at some point the brakes worked without using the trailer as a ground. The wiring underneath looks pretty amateurish so replacing all the brake wiring wouldn't be a terrible idea.

Here's what I'm working with.

Yuck

Awww yeah

 

[Fallon]

I'd go the other way around, pull the pin on the breakaway switch & make sure it properly energizes the brakes. Once that is sorted you know they work, then tackle the controller.

 

[dstig1]

You obviously know the answer: it's in the truck or the trailer. So continue on the path you are on: isolate the problem by figuring out which vehicle it is on, and then look for the reason on that part. There is no magic with electrical problems. Just start from one end and start checking continuity until you find a break. It is always painful, but with trailers it is almost always the trailer, not the truck, FWIW... Good luck

 

[Gunny]

I'd go the other way around, pull the pin on the breakaway switch & make sure it properly energizes the brakes. Once that is sorted you know they work, then tackle the controller.

Another vote for this method

 

[t320pilot]

If you hook to a different trailer that will test the truck brake controller.

 

[petebert]

I'll see if my neighbor has a trailer with brakes, this is the only one I have.

Okay I pulled the pin on the breakaway. I don't have a permanent battery for it yet but I have an extra car battery that I lugged over and touched the wires to while my son spun the first trailer tire in the wiring sequence. It would only lock up if I reversed the wires, so if negative ran to the breakaway and what I thought was the ground wire touched + on the battery the brakes locked up. If it makes any difference I did without the 7 pin attached to the truck.

 

[Fallon]

Brakes themselves don't care one bit about polarity, so you can't hook em up backwards & they will work just the same. I wouldn't switch the ground though. That might cause problems for the lights & stuff.

Check out etrailer.com they have some great docs on trailer repair & wiring.

 

[petebert]

I'm going to rewire all of the brakes. Getting a new 8' 7 point harness, roll of paired wires and a new breakaway. On the right side of the trailer I was able to get the front brake to work irregardless of the polarity but the rear tire wouldn't work at all so I think redoing this wiring will be a good start.

Should I ground onto the trailer anywhere? etrailer has a youtube video where they ground into the trailer before getting to the 7 point. But like I said in my original post, all the years this trailer has been in use and there's no trailer ground anywhere.

 

[aczlan]

I would ground to the trailer up front, then run an independent ground to the back (one to the brakes and one to the lights) that way you dont have to trust a possibly iffy ground connection at the lights or brakes

Aaron Z

 

[Fallon]

Ya, attach the ground wire on your plug to the frame somewhere & ground everything else to the frame as well. Make sure it's a good clean spot with metal to metal contact. No paint or rust. Cover it with paint or a corrosion inhibitor afterwards.

I agree if things are flakes, rewiring from the ground up is probably a better idea. You end up knowing how it's done & it's done right regardless of whatever is hiding or done in the past.