I just realized I had this in the wrong forum.

My car trailer (I bought yesterday) wiring has a plug that doesn't look anything like the two connectors that I found behind my bumper.

The trailer plug has 6 female spade type connectors in a circle. The truck has two plugs; one with 3 wires and one with 4 wires.

The trailer has electric brakes. What do I need to do to connect the trailer to the truck? I'm guessing I need a brake controller, for one?

 

I looked at the connectors more closely today.

The 4 wire plug has the running lights, four ways, turn signals and brake lights.

The 3 wire plug has no power when any lights are on. I don't know what that is.

In regards to the brake controller, I'm still looking into that.

The trailer 6 wire plug has running lights, brake, turn, a yellow (?) ground and a wire that goes into the box and isn't connected. There is a blue wire that goes to the brakes.

I'm figuring I need to get a 6 wire socket and adapt the 4 wire socket that's on the truck. I would need to run either a wire from a controller, or, I read somewhere, a wire from the brake lights to the brakes, to power them when the brake lights are on.

Do I need a controller or does the centrifugal force and the brake magnets regulate the trailer brakes?

If someone has a link to some info, I'd appreciate it. I've been searching and not getting detailed info.

EDIT: It looks like I need a controller.
2ND EDIT: Definitely need a controller. lol

 

Did you read the "READ FIRST" posts? You may well find your answers here: https://www.ford-trucks.com/forums/5...6-11-12-a.html

 

Do you have pictures of what you're looking at? Most trailers with brakes nowadays use the 7 round "RV" style plug.

The 4 pin plug on your truck has 3 shielded and one open right? That's a standard 4-flat plug. Used on trailers with only lights. (ground, left, right, tail)

There are adapter plugs out there that will plug into your 4 flat and have a 7 blade socket on the other end, with 2 or 3 extra pigtails on it to wire up the other functions.

If you're not confident in what you're dealing with, Uhaul can install the proper wiring/ plug, as well as a brake controller.

 

Thanks for the kind reply, 351Cleveland C4.

I have it figured out.

I was wrong when I said the 4 wire plug includes the running lights. For whatever reason, it has ground, brake and turn signals. No running lights. The unknown wire is black or brown w/ a white tracer. Never hot.

I'm going to have to tap a running light wire elsewhere.

FWIW, the plugs on the truck are round, typical Ford style connectors. I'm converting it to the round rv type that's on the trailer. I'll also add the blue trailer brake wire from the controller that I just bought to the round rv plug.

 

Ignore my above posts. I have it all figured out, and I'll explain it here in hopes I can help someone searching in the future.

First, 351Cleveland C4, I didn't have a flat plug w/ 3 shielded and one unshielded. The truck had no trailer harness or brake controller of any kind.

First, I added a brake controller. I didn't buy anything fancy. It seems older designs had a pendulum inside them to sense braking force, and had to be mounted level. The newer ones can be mounted in any direction, as they are electronic. They seem to go up in price as the number of axles they can control increases. There are some with other features that aren't necessary for me.
I couldn't find anything substantial under the dash to mount it to. I wedged it in the small storage pocket on the dash, to the right of the steering wheel, after I drilled a hole in the back of the pocket for the wires.
There's a power wire, a ground wire, a wire that goes to the brake switch (to feed the brake lights when you use the button on the controller to operate the trailer brakes separately), and a wire that goes to the light harness plug at the rear for the trailer brakes. Oh, mine required a circuit breaker on the power wire.

I was completely wrong when I described what I thought were the correct connectors to work with.

There is a connector that in the harness on the drivers side, behind the bumper. It is above the two connectors that I described above. I bought a pigtail (with 4 wires) that is inserted in the middle of this connector. This had a flat connector on it which I cut off, because I have a receptacle mounted on the hitch, and connected the wires directly to it. The 4 wires are: ground, running lights, left turn and right turn. The brake lights and 4-ways are fed through the turn signal wires. The 5th wire, coming from the brake controller, to power the electric brakes.

I also bought a plug for the wires going from the trailer to the receptacle on the truck. I was sure to get one that matched the receptacle and had the same number of wires. The plug that was on those wires, was matched to the truck belonging to the trailer's previous owner.

Being a used trailer, I pulled the drums to check the bearings and brakes. The brakes needed adjusting, but everything else looked good.

I have a break-away cable on the brakes and safety chains.

I took it for an unloaded test ride today. Everything works great! I'm going to load my Mustang tomorrow, and give it the "acid test".

 

Glad you got it figured.

 

You will have a connector under the dash at or near the trans tunnel, this plug is used to connect a brake controller. You can get the mating plug from Ford or a parts house. Once that is done you should have power to the 7 pin round bargman connecter at the back of the truck. This truck is already wired for a brake controller, all you have to do is put it in. The trailer fusing is already under the hood in the power distribution box. Don't let some minimum wage flunky hack up your electrical system.