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

 

[George2615]

If the trailer was wired to a 4 pin plug with the brakes tied into the brake light circuit, the brakes would lock up every time the brakes were applied since they would apply full vehicle voltage to the brakes this way.

Since Russell rewired the trailer and now the brakes lock up when the parking lights come on it is wired wrong.

He says that with the trailer disconnected and the parking light circuit turned on he is reading 7.6 volts to the trailer brake wire. This tells me the controller he bought and had installed is wired wrong. It should not put voltage to the trailer brake wire (blue) unless truck brakes or the controller manual brake lever is applied.

If he is getting this voltage reading with the trailer wiring plug connected to the truck then trailer parking light circuit is back feeding into the controller through a crossed or wrongly wired trailer harness.

 

[Diamondpilot]

If the trailer was wired to a 4 pin plug with the brakes tied into the brake light circuit, the brakes would lock up every time the brakes were applied since they would apply full vehicle voltage to the brakes this way. Since Russell rewired the trailer and now the brakes lock up when the parking lights come on it is wired wrong.
He says that with the trailer disconnected and the parking light circuit turned on he is reading 7.6 volts to the trailer brake wire. This tells me the controller he bought and had installed is wired wrong. It should not put voltage to the trailer brake wire (blue) unless truck brakes or the controller manual brake lever is applied.
If he is getting this voltage reading with the trailer wiring plug connected to the truck then trailer parking light circuit is back feeding into the controller through a crossed or wrongly wired trailer harness.

That is what I think also George. Like I said the colors do not go red-red, black-black, ect, ect, necessarily. You have to follow the schematic. They seem to love to make things harder than they need to be. You would think they would all get together and get everyone on the same page but that would be too simple.

Chris

 

[Diamondpilot]

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.

After rethinking this laying in bed, my best guess and where I would start is the wiring between the plug and controller. I believe the Voyager has 4 wires if I remember right. I have installed dozens of these in my trailer business so I am familiar but going by memory here. Anyway here is how it should be wired.


Ford Plug Controller

White Wire Black Wire
Red Wire Red Wire
Blue Wire Blue Wire
Green Wire Pink/Green/or any other Color
Black Wire Not used ------------------------------


Again this is from memory. My guess is you have the black wire of the plug going to the black wire of the controller. This black wire from the plug is for dash lights. Some controllers have dimming lights but 95% do not, only high end $400 controllers usually have them and use this 5th lead. Anyway what is happening is when you turn on the trucks lights its back feeding voltage to the brakes and locking them up.

Hope this helps. I am also PMing you my phone number if I can help any. I am by no means a expert but have wired 100's of trailers and trucks in my little marine/trailer business so I have seen lots of weird things.

Chris

 

[jones6780]

I surely hope this was my last dumb mistake for the year. I went back out today and started with the controller since I had rewired the trailer and I KNEW it was right. Well as it turns out there were two diagrams for the trailer connection plus I was looking at the slot used to index the the plug when installed. As it turned out the slot to index the plug is shown on the bottom in the diagram but on the truck it is on top. So I had wires all screwed up on the trailer side. I rewired the connector and everything works, brakes included. Thanks for all the help guys. Here are the 2 different wiring diagrams note the location of the brown wire and the index slot at the bottom. Also here is a shot of the trailer I bought cheap. $900.00 was worth it even with my wiring problems. It has 3500 lb axels and is a solid trailer. I have a 1700 Ford to haul and this will work fine for me. Thanks again.

Russell

 

[Diamondpilot]

I surely hope this was my last dumb mistake for the year. I went back out today and started with the controller since I had rewired the trailer and I KNEW it was right. Well as it turns out there were two diagrams for the trailer connection plus I was looking at the slot used to index the the plug when installed. As it turned out the slot to index the plug is shown on the bottom in the diagram but on the truck it is on top. So I had wires all screwed up on the trailer side. I rewired the connector and everything works, brakes included. Thanks for all the help guys. Here are the 2 different wiring diagrams note the location of the brown wire and the index slot at the bottom. Also here is a shot of the trailer I bought cheap. $900.00 was worth it even with my wiring problems. It has 3500 lb axels and is a solid trailer. I have a 1700 Ford to haul and this will work fine for me. Thanks again.

Russell

Glad you got it fixed. Been there done that. If there is a stupid mistake like having something out 180 degrees like you did I have done it 10 times over. My first bet was on the controller to the Ford Plug. My second bet was the wiring on the trailer. Glad it was a simple fix.

On a side note, you may want to pick up some fenders for that trailer. In my state they don't stop you for much but no fenders is one they will get you on. They are cheap, about $30 each or you can even find a fab shop to make some out of aluminum diamond plate and make them bolt on with welded on studs and wing nuts for easy removal. Could be make quick in a brake out of some scrape for under $100 around here.

Chris

 

[George2615]

I agree with Chris to get a set of fenders. Trailers in most states require them and local DOT stops will ticket you without them. Also check your tire sidewalls to make sure they say for trailer use. Its hard to tell from the pic but they look like passenger car tires which is another ticket item. Glad you got the wiring figured out. I knew it had to be something simple.

 

[Diamondpilot]

They will not get you for truck or passenger tires around here as long as you are within the load spec and they are in good shape.

They will get you for reusing mobile home axles and tires over on a trailer. They have a mileage limit stamped on them or one time use stamped on them.

Chris

 

[jones6780]

This is Georgia. I see mobile home axels on trailers all the time. I was looking at fenders. The tires are passenger tires and I will use them until they need replacing. I won't be hauling very far or heavy loads. Thanks agin for the info.

Russell