Help Me Replace My Trailer Wiring Harness

So I got the truck in 2010 used, its an 06 4 banger, so I am assuming the hitch and light harness are aftermarket. Ever since I got the truck I have been having troubles with the lights on trailers, and the electric brakes wouldnt work either. Yes, I have the controller hooked up.

Can I just rip this old wiring harness out and install a new plug n play one that I have seen? I dont wanna deal with splicing wires and stuff because I will just screw it up more. Right off the back of the plug there is a yellow wire that sticks out about 4 inches then goes nowhere. Wtf?

Any suggestions? I can get picks if you guys need them.

 

With running lights and hazards on


Random yellow wire....


Box thing behind left tail light

 

Anyone?

 

Personally I'd just pay the few hundred bucks to have a reputable shop tear it out and start from zero. I hate screwing around

 

Would they make sure the brake controller is wired properly too?

 

they should if they are reputable, just make sure to point out that it's one of your concerns

 

I am not sure, but I don't think the "box" is a brake controller. I think it it your convertor box for the bulbs to plug(i.e. 3 bulbs or whatever).

 

Factory add on is a flat 4 pin.
It is 100 times better than aftermarket. It uses the trucks system for power. Those converter boxes always go bad.

Running the extra wires for the brake and acc. Is not that big a deal and if the controller is run correctly then you can just run new wiring to make it all new.

 

It looks like the PO spliced into the main harness. You can buy a plug and play harness and use it, but you should first remove this set up and re connect all the wiring spliced into the main harness.

 

I put one of those plug-and-play harnesses in mine. Works great. I haven't looked at a brake controller hookup, but I would not use any of the outputs from the converter box for trailer brakes. The box is designed to operate only the standard trailer lights, and not anything else.

 

It looks like someone bought a 7 pin harness and only hooked up the wires that pertain to the lights (no brake wiring).

The box is a convertor that make the trailer signal/brake lights work properly with the Toyota seperate brake and turn bulbs.

What did you hook the brake controller to? Looks like you are missing the wiring from the controller to the socket.

 

I would start from scratch.

 

The brake controller and all trailer wiring was already installed when I bought the truck two years ago. Never had problems with lights until recently they randomly just dont work. I want to get rid of them all and install a new plug and pay harness, but I need the brake controller wired in as well

 

Where can I find the plug and play harness tha connects to the existing tail light plugs then runs down to the trailer plug? I found some but I dont want the flat 4 pin connector, I'm looking for one with the round 7 pin. I can't find one anywhere

 

Your best bet is probably to use this with a 4 pin plug and play harness:

http://accessories.etrailer.com/trailer/4 Pin To 7 Pin Adapter

Just add the wires required for your trailer brake system.

 

This is where I got mine for my 2012. It works great and i had it installed in 10 minutes. Here's a link for the 2010.

http://www.jcwhitney.com/t-connector-kits/p2018063.jcwx?filterid=d2193y2010g2

 

Any of those systems that just plug into your existing tail lights are going to be a flat 4. You could splice them into the correct pins on a 7 pin but you won't have the complete function of a 7 pin wiring harness which is what it looks like the previous owner did.

You keep mentioning a brake controller, do you have one installed? If you did, it would be in the cab somewhere most likely. That box you took a picture of is not a brake controller, it's just a control box for the lights.

 

That 4 pin connector will never operate the brakes, if indeed you have a controller. I went down to autozone/napa/orielly/etc and bought a 7 pin round connector, do your research and get all the wires spliced to where they belong, and then you can use your brake controller as well.

 

^^^One of those for $16 plus the one I posted to connect to the taillights for the 4 pin will work. The one above has the extra wires you can tie into your existing brake controller wires. I think all this will work anyway. There's a pic on the item page that points to what the additional wires are for.

 

I have a brake controller mounted under my steering whee, can't remember what model. I know what each wire is in a 4 pin and I know they wont control the brakes. The reason I wanted the 7 pin instead is so it have the extra slots to get brakes hooked up. The only thing I don't know how to do is wire brakes and the controller. Lights are a piece of cake.