No power to trailer plug at rear of F350

Congrats, you have found Ford's super secret fuse that drove everyone mad for years!

There usually is an open harness plug under the dash. When you buy a brake controller, the instructions should come with it. The better units will have a pigtail which will plug right into the other half of the open harness plug.

If the kit you have has the pigtail connector, but loose wires needing to be connected, see if the color of the wires match those on the open connector. Then match the color of each wire.

Some years of trucks will have a heavy duty flasher to install in the Powerbox to accommodate the extra trailer lights.

OK ON SOME OF THE TRAILER BRAKE PLUGS ( THE PLUG FROM BRAKE BOX TO TRUCK ) THE POWWER WIRE IS IN THE WRONG PLACE ,THE PIN AT TRUCK SIDE MAY NEED TO BE MOVED IN THE PLUG,

First thing is your van equipped with a trailer brake controller and is it working. This is usually a small box that is installed inside the vehicle and is needed to operate the brakes. Next what type of plug do you have on the vehicle to plug the trailer into some plugs do not support wiring for trailer brakes. If you have a aftermarket trailer brake controller it will not be fused in the fuse panel so you will to locate a inline fuse used to power up the controller. Hope this helps.

Alot of these trucks have the wiring hook up under the dash or at rear bumper area where you can just plug the wire harness from controler to it, but if not they are simple to wire and then you must level by following the instructions,you would wire it to power and ground then one wire to brake switch and the last wire goes to tow connector for electric brake on the trailer. for more help google how to install brake controller there you will find wiring diagrams and videos.

Depending on the unit you need to adjust one or two knobs to get the brakes to work If you have an ohm volt meter you can test to see if the brake line has power at the plug from the truck if it does then plug it in have someone hold the brake pedal down and with the ohm volt meter ground the black lead of the meter to the frame or the backing plate. Next yest to see if you have voltage to the wire by probing the wire one Will be ground and the other will be positive if it does not have power then you may have a fuse on the trailer your not seeing you will have to plug in the plug and follow the power along the path of the wire for the brake. test on each side of the plug then at each junction that you see working back to the trailer brakes. If you have power then try turning the control knob on the controller half way on one or both knobs you may have. once you have turned the knob see if there are any lights on the brake light controller if there is then have someone in the truck with the key on go to the rear by the trailer wheels and have them press on the brake listen to see if you can hear the brakes moving or humming if they are not then you will have to remove the axle hub ans look to see if the surfaces are rusted or the floating magnets are frozen if they are loosen them up then sand both the brake pad side and the surface where the magnet connects reinstall and try again if you have power and the brakes are still not working get back to me and I will give you some more testing information. Hope this helps and thanks for using fix ya.

There is a relay/fuse box under the hood the max fuse for this is in there.

Do you mean nothing works or just the power lead? If nothing works I would check the ground. If just the power lead doesn't work on the I know on the older superdutys the large fuses had to be installed in the fuse box under the hood to make it work. They were usually in the bag with the trailer brake controller wiring and had directions on where they went. Hope it helps

easiest way is to also buy the wiring adapter almost all elect brake units sell a vehicle specific wire harness that u unplug brake wire harness plug in other harness than plug in brake harness and just connect the wires to elect brake controller eliminates cutting and splicing ur brake harness about $18

a brake controller has 4 wires on it, Black, white, blue,red.

Black is positive battery 12 volts connect to 30 amp circuit breaker to the battery

White goes to good solid ground

red connects to white wire from the brake switch

blue wire connects to 7 way trailer connector at rear of truck. If the truck has trailer package you will find the blue wire and red wires under brake booster taped to the harness you can connect your blue brake control wire to that blue wire. At the rear of the truck the other end of the blue wire will be taped to a harness under the rear of the truck. you will have to now connect the blue wire to the blue input on your 7 way connector