Trailer Brake Issues

So I went to pick up the livestock trailer and knew the wiring was kinda screwy. The brake lights came on when i hooked to the trailer and the parking lights and trailer brakes came on when I pressed the brake pedal, all the while the brake controller said no trailer connected. I went into the plugs and moved wires to their respective places as per the molded lettering and i have brake lights and turn signals but no parking lights now. Also i have blue wire connected to blue wire and the brake control still says no trailer connected and it worked on the neighbors trailer last month. The only thing is i am using the yellow (normally aux. wires) as ground (hooked to blade labeled white) as no white wires were in either side and the truck side has no black or red wire I figure this is why there are no parking lights, where do those wires run to so i can add them? but that doesn"t explain no brake control. Any ideas on what the deal is? Thanks. Jared M

If you scroll down on this page it will give you wiring diagrams.

Also make sure you run a ground from the plug to the trailer and have ground wired into the plug onthe truck.

Usually when all lights are acting goofy it is lack of ground.
Trailer and truck plugs.

Not sure what you have for a truck, Jared, but on some the wiring to a factory trailer plug does not match the customary color coding. First thing I'd do is get that back the way it was when it worked on the friend's trailer. YOu might have to use a test light to trace anything you lost track of

Then start in on your trailer. You don't say whether this is a 7- blade or a 6- or 7-pin connector. A lot of goosenecks tend to come with the 6-pin, and a lot of weird things get done converting them over to 7-blade.

A couple of things to watch for. If it is a six-pin, those came two ways, one with the center pin for the brakes and the other with the center pin for your 12v hot, so once you're sure your truck is right, you may have to swap those two pins on the trailer end to get your brakes to show up on the controller and have them work right. The other is to just go slow. Myself, I have to be careful and triple check what I'm doing as it doesn't take long for my feeble minds to get twisted up working with the mirror images that the two sides of the plug make.

And Gary makes a very good point about your ground. You can't have enough grounds on the truck or the trailer, and you really need to have them connected directly through the plug. Grounding through the hitch is not reliable.

Gary's link is good But I'll toss another one in that also includes some troubleshooting ideas.
Wiring at etrailer

I'll second that ground. When I have to do anything with the lights on any of my trailers I always use my jumper cables to provide a temporary ground between the pickup and the trailer. I even have a short jumper wire that allows me to connect the pickup and trailer through a single prong, hence the need for a ground, without actually plugging the sockets together. Bud

I've never seen 7 blade trailers wired like shown on Gary's link. Scotty's link shows how I've always seen them.
I agree with making sure the ground connection is good with strange light problems. I'll add that I always solder every connection and use heat shrink tubing to seal out moisture. You'd be surprised how trouble free trailer wiring can be when soldered and sealed.

I'd just add to Brian's comments (the heat shrink made me think of it), your problem is just squirrelly enough that it's worth looking at each plug that you've been into to look and feel thoroughly for any stray, frizzy strands of wire that might be making contact with an adjacent terminal inside the plug. BTDT.

We figured it out, I did have it right I just blew the fuse for the parking lights and the brake wire on the trailer is bad somewhere becuase we hooked to a friends gooseneck and the brake controller recognized it as connected. Thanks for the help guys. Jared