Constant power at blue wire for trailer brakes?

Hi All,

I bought an old landscape trailer and replaced the brakes but they are not working. I've spent some time looking into this and believe the issue is up front somewhere as I appear to be getting a constant 12v+ power on the blue wire all the time, so when the brake pedal is pressed nothing is happening.

There's constant power at the trailer plug but also coming from the oem wire harness at the blue wire as well. Not sure if it's an intermittent issue but the one time I checked the brakes were working using the brake controller slide button but not when pressing the brakes so the assumption is the red wire and brake switch are fine?

I have a Curt Triflex proportion controller installed which has always worked well on my dump trailer. I checked a new Curt controller just to make sure and there was no difference.

Anyone have this issue or can advise on what the fix might be?

Thx.

 

without digging into it further, I did a decent amount of towing with the taco, and now primarily use a different truck, but 100% of my electrical problems were NOT the controller/wiring harness. It was always a fuse or something with the trailer, bad ground, ect.

when you say there’s constant power at the plug are you saying the trailer brakes pin on the truck side has constant power?


also assuming you have magnets, can you HEAR the brakes engage on both sides when you have someone step on the brakes? If you only hear it on one side, there’s a short somewhere.

 

I’m assuming you already tested it like this, which directed you to think it was the controller?

https://www.etrailer.com/question-310692.html

also, are you using a test light, or a multimeter?

 

the trailer brakes are brand new with new wires I ran directly to each. I also changed the ground location and made sure it was on bare metal.
Correct, the truck side blue pin has constant 12v power when the brake pedal is not pressed. I'm going to re-wire all the lights new since the wires are a mess but everything else works fine.

 

yes, i've been reading alot of the posts on etrailer. I'm using a multimeter and when I cut the blue wire at the back of the brake controller i was still getting 12+v coming from the blue wire from the taco factory plug, without the brake pressed. Fuses are good but I didn't check the relay yet.

 

Damn. That points at a bad controller but I know you said you tried a different one already.

New question; is it always exactly 12v being applied?

if you start driving with the trailer, are the brakes slowing you down? If they’re 12v constantly they should be locked up.

 

Have you seen this one about Curt controllers? I’ve never heard of this

https://www.etrailer.com/question-214505.html

but I’ve also always used tekonsha

 

no with constant power they don't seem to engage at all? My electrical knowledge is limited but it doesn't make sense to me so I suspect something else is going on.
I'm wondering if its a combination of things but I'm going to rewire the trailer from ground up to rule it out. I might change the wire harness as well, even though its new, just to rule that out too.

The strange thing is when I backed my truck up to both trailers to check for the brake 'hum' with the pedal pressed the other day, they both were engaged and worked on both trailers but they were definitely not working over the weekend on the new utility trailer when i was pulling my tractor, and it's 6200+lbs loaded so i need to figure out asap.

I need to check my dump trailer as that all factory and has always worked and I'll report back.

 

I have not, interesting and thank you. I'm going to have to check the amperage. I called Curt and they told me there wasn't supposed to be constant power at the truck side blue trailer pin? Lots of conflicting information.

 

Yeah I would assume if they were getting 12v they would be locked up or close to locked up so that would be a red flag for me.

I have no clue about amps I’m just a zip tie mechanic lol.

 

I’m sorry man I hate electrical issues

 

the trailer was old and a mess so there's a good chance its something with the trailer (it seems). going to start over with all new wiring and go from there.