well I am going to need to use my truck (78 f-150) for towing a trailer with electric brakes. The truck has the tow hitch and electronic brake controller in it, but the previous owner disconnected the controller (he just disconnected the fuse from the positive wire) and I have run into an issue that hopefully somebody can help me with.

Current setup:

white wire is run from neg side of the battery to the white wire on the brake controller.

Red wire from the brake controller is connected to the brake stop light switch under the dash.

Black wire with fuse running from the positive side of the battery to the blue wire on the controller.

Now here is where I am not sure that the po ran the wiring right, but I am not sure.

There is 2 black wires running from the trailer connector on the back of the truck, one goes to the black wire on the brake controller in the truck and the other one is spliced into the wire going to the positive side of the battery.

when I plug in the wiring connector to the back of the brake controller the green light on the controller stays on even with the truck turned off.

Can somebody help me with this????

 

I am not sure I am following. It sounds to me like the po used the power feed to the controller to also act as a charge line to the trailer battery. Is this a travel trailer with a battery and are you connecting to a standard seven pin connector on your truck?

Steve

 

I have no clue what the po towed as I got it off ebay and have no contact with him.

the truck has a standard 7-pin connector on it. Currently there are 2 wires running from it to the front of the truck. One goes to the black wire on the brake controller and the other is connected to the positive wire running from the battery to the controller.

I will be towing a trailer with electronic brakes. The trailer is a draft beer trailer we use at outdoor events. It is a run of the mill 16' dual axle enclosed trailer.

Can I disconnect the wire that runs from the positive terminal to the trailer connector? If I do what will that effect? Shouldn't the light on the controller go off if the truck is turned off?

 

John,

Take a look at this video and see if it helps Brake Controller Installation - 1979 Ford F-250 Video | etrailer.com .

Controller wiring is all the same. Yes, the light should go off when the truck is turned off. The lead off the battery to the seven pin connector is the charge lead that charges the trailer battery when you are driving. You do need a battery source on the trailer to insure the trailer brakes will activate if it were to separate from the truck.

Steve

 

The voyager controller I have leaves the green light on any time a trailer is connected (a trailer with brakes), even with the key off, as long as the brake controller has power.

The blue wire on the controllers I've used has always been the brake signal to the trailer, and the black wire on the controller was the positive feed.

 

Thanks for the video, but mine is not wired like that. there are no circuit breakers mounted anywhere, only a inline fuse which is part of the wire going from the battery to the brake controller. Mine also doesn't have the flat 4 pin connector the wires for the 7 pin connector are wired directly to where they are suppose to go.

 

Agree. The blue is always to the trailer brakes and black is always the charge lead. I was anticipating a switchable power supply to the controller, but you are right. The topic of when the controller is lit is an interesting one and with the build-in pigtails, it actually varies by manufacturer. My thought was the controller would work as op posted. What do you think?

Steve

Steve

 

So is it possible that the problem I have is that the wires are connected wrong. Meaning the wire coming from the battery should go to the black wire on the controller and the wire coming from the trailer connector should go to the blue wire on the controller?

 

Fair enough. It still strikes me the essentials are in place. One of the things that controller manufacturers stress in classes is controllers should be fused with auto resetting fuses rather than standard fuses, although most directions fail to mention that. The flat four pin is simply an add-on on many seven pins. You are going to have to add a switch or do something to cut the power to the controller in this case. Some of the newer models go to sleep on their own, if they do not sense trailer brakes.

Why not hook it up in a safe area and give it a try. I think the controller will work. Otherwise, if you would rather, most RV service centers can hook the seven pin on your truck up to a simulator and tell you in 30 seconds whether it is working.

Good luck,

Steve

 

Unless someone has really screwed up, this is all color coded. There will be a blue wire at the seven pin feeding the trailer brakes and the black will be powered to charge the trailer battery. Typically, if the truck is wired to charge the trailer battery, you will have a blue and a black lead coming into the seven pin on the truck.

Steve

Steve

 

well I switched the wires (the one from the battery now is attached to the black wire on the controller and the blue wire on the controller is now going to the trailer connector) and still when the truck is off and no trailer connected I still get a green light that is on

 

What happens when you hit the brake pedal?

 

it changes from green to light green to a yellowish color with no trailer attached

 

Sounds like it might be working. Hold down the brake pedal and then turn the thumb wheel for more braking power, and the LED should turn to red. But it might have to have the trailer hooked up for this to work.