2004 Ford Freestar wiring for trailer

[lundboat]

Hi,

I need to wire my Ford Freestar (minivan) to accept a 7 pin plug.

There are 4 wires already attached near the bumper that I am assuming are for trailer wiring.

They are white, yellow, brown, green. And they go into a round 4 pin adapter.

The wiring harness I got from UHAUL has 4 naked wires (the same colors thank God). The other 3 wires I'm just ignoring for the time being as I still need to install the electric brake control. Right now, my only priority is getting the lights to work.

So... I cut the adapter off the car and attached all the wires to their respective colors on my UHAUL harness. With one exception, the white wire on the UHAUL harness was not a naked wire... it had a ring on the end of it, so I bolted it to the frame. This leaves the white wire from the car not attached to anything. Is this my problem?

As you can imagine...my lights don't work (which brings me on here) hoping for help.

When I went to Schucks auto supply they showed me a completely different wire harness that they said I needed for my car... this wire harness had some sort of converter box and the instructions ignored the wires from my car that I'm working with and said to wire straight into the tail lights.

thanks everyone for your help.

 

[Silvertip]

Re: 2004 Ford Freestar wiring for trailer

The white wire is the ground wire and if you have the wire in the U-Haul harness attached to a solid ground (the frame) the white wire in Ford wiring should not be needed as it too is ground. Just make sure the point you attached the ground wire to has all the paint and undercoating removed so its contacting bare metal. Then coat that attachement to prevent corrosion. Now then, with the trailer disconnected, using a test light or voltmeter, test the brown wire to see if 12V is present with the lights on. If so, thats good. If not, you need to figure out why. The brown wire is the tail light and side marker light wire. Then repeat the test for the yellow and green wires. These are the turn signal wires. You can test those by turning on the 4-way (emergency) flashers. If everything is ok on the car, the problem is at the trailer and it usually turns out to be a bad ground either at the white wire or at the lamp assemblies. Manufacturers rely on the bolts that secure the lamps to the trailer for a ground and that connection often fails. If you have a battery charger, connect the NEG clip to the white terminal or trailer frame. Then touch each of the other three pins with the POS clip and see if the applicable light works. If not, the trailer wiring needs attention.