Wiring Needed for Tow Vehicle to Provide Maintenance Charge to Trailer Battery

Question:

Dear Sir, I have a 2016 Ford Fusion, basic model, and I am buying a travel trailer made by Taylor Coach. Taylor will set up the battery on the trailer so it can be charged by the car while I am driving. Now what do I so that the car can do its part? Is there some sort of kit that I can get to wire up the battery so that it connects to the trailer to charge the battery there?

asked by: Dan C

Expert Reply:

Your vehicle can provide the trailer's battery with a maintenance charge through the 12V power wire at the 7-Way trailer connector at the rear of the vehicle. This will allow the vehicle's battery to help maintain the trailer's battery whenever the trailer and vehicle are connected.

The Battery Isolation Solenoid # PK5231201 that you referenced can be installed on the vehicle to limit the draw on the vehicle's battery by the trailer. This solenoid will stop power to the trailer when the vehicle's ignition is turned off so that the trailer will not drain the vehicle's battery. If you plan on un-plugging the trailer from your vehicle when not towing, a battery solenoid is not required.

If you need to add a 7-Way trailer connector at the rear of your 2016 Ford Fusion you will want a 4-Pole wiring harness and the etrailer.com # ETBC7 installation kit. The 4-Pole wiring harness I recommend for your Fusion is the T-One Vehicle Wiring Harness # 118574. I have attached an installation video of this wiring harness for you. The 4- and 7-Way vehicle end connector included with the # ETBC7 kit will plug into the # 118574 harness for trailer brake, turn, and taillight signals.

To have 12V power, electric trailer brakes, and a reverse light signal, the wires at the back of the 4- and 7-Way socket will need to be ran to the appropriate locations. The 12V power wire will need to be ran to the vehicle battery. The brake wire will connect to a brake controller inside the vehicle. The reverse light wire will need to splice into the vehicle's reverse light circuit. I have attached the installation instructions for the # ETBC7 kit to walk you through this installation.

If you need a brake controller for your trailer, I recommend the Tekonsha Prodigy P2 Trailer Brake Controller # 90885. I have attached a review video of this controller for you.

If you need a trailer hitch for your Fusion, I recommend the Curt Class II Receiver Hitch # C12091. I have attached an installation video of this hitch for you. I have also linked a help article on choosing a ball mount, and the product page for the ball mounts that we offer for 1-1/4 inch receivers.

I have also attached some help articles on towing a trailer for you. It is a good idea to check the owner's manual of your 2016 Fusion for the towing capacity to be sure that the trailer will not exceed the manufacturer's towing capacity for your vehicle. Based on what I found in the owner's manual, depending on the engine, the Fusion has either a 1,000 or 2,000 pound towing capacity.