Adding a 7-Way Trailer Connector to a 2010 Ford F-150 with Factory Installed 4-Way Flat Connector

Question:

want to convert 4 pin to 7 pin trl tow and install brake control. i have found brake control plug under dash and have located trler tow battery charge relay location and battery charge fuse location, neither are installed however trk appears to be set up to plug both of those in...what i need is a p/n for harness to plug into existing harness in back of trk to convert from 4 pin to 7 pin.

asked by: Chris P

Expert Reply:

To convert the factory 4-Way flat trailer connector on the back of your 2010 Ford F-150, you will need Adapter 4 Pole to 7 Pole and 4 Pole, # 37185. You will plug the factory 4-Way into the back of the adapter and hardwire the remaining 4 wires.

The white wire gets grounded to the vehicle frame. The blue wire on the adapter carries the brake controller output voltage, and the black adapter wire carries the 12-volt accessory voltage for any trailer mounted accessories that might need power. If you trace the wiring harness leading from the existing factory 4-pole, you should find that the harness plugs into a connector along the drivers side frame rail near the back axle. If you peel back the wire loom on the other side of the connector, you should find a blue and an orange or red wire in the harness. The white blue adapter wire would tap into the blue wire on the harness and the black adapter wire would tap into the red or orange wire. The last wire can be connected to the reverse light wire behind one of the tail lights. If the trailer does not have reverse lights or an electric reverse lock out, this wire can be taped up and stowed out of the way. I have included a video showing a typical installation of this adapter.

If you do not already have a brake controller, I would recommend the Tekonsha Prodigy, part # 90885. The P2 is very easy to install and set up, which helps make it our best selling brake controller. You will also need the brake controller wiring adapter, part # 22292 that would allow you to plug the controller into the connecter under the dash.

expert reply by: Michael H