Elect trailer brake problem

[jones6780]

I just bought a used trailer, 16 ft plus 2 ft beavertail. It had a 4 wire flat connector and elect brakes wired into the brake lights. I rewired it and bought a Voyager brake controller for the 04 F150 with factory tow package and both 4 and 7 pin connectors. The problem is when setting the controller I could never lock the brakes. When driving home I turned on the parking lights and LOOK OUT, the trailer brakes locked up. I disconnected the trailer and checked the wiring on the truck side and everything looked good. I took a voltage meter to the brake controller connection and with lights off the blue wire showed 0 volts but when I turned on the lights on there was 7.6 V. How can the lights effect the brake circuit? This truck has never had a brake controller or pulled a trailer with elect brakes. HELP!!

RusseLL in Lizella, GA.

 

[MarkLeininger]

Not sure I understand what you measured and what the connector setup is:

1. When you say you "took a voltage meter to the brake controller connection" do you mean you disconnected the trailer side of the connector and inserted a meter into the pin on the truck side that brings power from the brake controller (normally a blue wire)? Or did you have the trailer connected when you measured the voltage on the brake controller connection?

2. Also I'm not clear what kind of connectors you're now using. If the trailer came with a 4 wire flat connector on it, and you plugged it into a factory provided 4 wire connector on the truck, there shouldn't be a wire carrying power from the brake controller. So, did you change the trailer connector to be a 7 pin?

 

[J_J]

I just bought a used trailer, 16 ft plus 2 ft beavertail. It had a 4 wire flat connector and elect brakes wired into the brake lights. I rewired it and bought a Voyager brake controller for the 04 F150 with factory tow package and both 4 and 7 pin connectors. The problem is when setting the controller I could never lock the brakes. When driving home I turned on the parking lights and LOOK OUT, the trailer brakes locked up. I disconnected the trailer and checked the wiring on the truck side and everything looked good. I took a voltage meter to the brake controller connection and with lights off the blue wire showed 0 volts but when I turned on the lights on there was 7.6 V. How can the lights effect the brake circuit? This truck has never had a brake controller or pulled a trailer with elect brakes. HELP!!

RusseLL in Lizella, GA.

I don't believe you have told us everything. Anyway, here is a guide. I don't understand how you wired up your trailer brakes with a 4 pin unless you used the white wire for the brakes. Otherwise, the brake controller wire went back to the white wire on the truck side, and the wire from the trailer brakes wire to the white side. A lot of people do not use the white wire, but use ball connection for ground. This would work if you had a good enough ground.

Trailer Wiring Diagram For 4 Way, 5 Way, 6 Way and 7 Way circuits

 

[wushaw]

You can't have brakes with a 4pin connector, you get full brakes when you turn on the parking lamps.
You need a 6 or 7 pin connector and wired accordingly, wire size and pinned correctly.
Here is a good guide to help.
How to Wire your Car or Truck for Trailer Lights

 

[jones6780]

I bought it with 4 pin and the lights worked to bring it home.
I have rewired it for 7 pin like on the truck and used a wiring diagram/color code. Lights work, brakes are not connected to any light wires as they are strictly a brake circuit. I feel like the problem is on the truck side.

RusseLL in Lizella Ga.

 

[JohnDeere4300]

I don't believe you have told us everything. Anyway, here is a guide. I don't understand how you wired up your trailer brakes with a 4 pin unless you used the white wire for the brakes. Otherwise, the brake controller wire went back to the white wire on the truck side, and the wire from the trailer brakes wire to the white side. A lot of people do not use the white wire, but use ball connection for ground. This would work if you had a good enough ground.

Trailer Wiring Diagram For 4 Way, 5 Way, 6 Way and 7 Way circuits

I don't know how he wired it up to a 4-pin either, i thought the white wire was the ground.

And the way it sounds is, when he had it hooked up to the lights and turn them on they locked up.
so really they didn't have power for the brakes until the lights was turned on.

 

[Diamondpilot]

On the Fords of late, not sure about your year, they have a diagram on the 7 pin plug cover. Check this with a test light or volt meter and no trailer to make sure you have good signal from the truck. As others have said there is no interconnect between the lights on a trailer and the brakes except all circuits on a trailer share a common ground.

One other last thing is 75% of the time the color codes on brake controllers do not match up with the pig tail you plug into (Ford plug). So what I am saying is white does not go to white, ect, ect. Follow the printed wiring diagram. My best guess is if this is he problem you hooked up the dash light dim lead off the Ford plug black, to the blue wire on the brake controller or something like that.

Anyway here is the Ford codes.

white=ground
red=12 volt feed
green=stop lamp
black=illumination feed
blue=trailer brakes

The other possibility is when you cut off the 4 pin connector on the trailer and hooked up the 7 pin connector you bought you could have gotten some wires crossed. On many plugs there is 2 ways to wire them. Check the directions or follow what the other guys posted. Either way you have something wired wrong.

Chris

 

[J_J]

You can't have brakes with a 4pin connector, you get full brakes when you turn on the parking lamps.
You need a 6 or 7 pin connector and wired accordingly, wire size and pinned correctly.
Here is a good guide to help.
How to Wire your Car or Truck for Trailer Lights

It can and has been done. I am not saying that it is the correct way, but it can be done as I stated. We know now that he used a 7 pin plug, but still don't know what diagram he used. I went to U-Haul place , and he drew up a diagram that was different than the instructions that came with the plug. It is best if you use a meter to verify things with a helper if possible.

 

[tommu56]

I'm not sure if the fords have the fuse in the fuse panel for the brakes the chevy's I had didn't neither does the ram I have now
Did you put the fuse in the fuse block to frrd tne brakes?
tom

 

[Diamondpilot]

Fords don't use a fuse like GM and others but do use a relay that comes with the kit. All it does though is complete the charging circuit to the 7 pin plug to charge brake away batteries or any other trailer battery installed and wired into the plug properly.

I still lean toward the controller/Ford Plug lead (pigtail) wired improperly or he wired the 7 pin plug on the trailer wrong.

Chris