ZX3 Trailer Lights Wiring Tips
Ford Focus ZX3 trailer wiring information is hard to come by for some reason. People here are quick to say "buy the Haynes manual, look at the wiring diagram" which is certainly good advice, but not what you're looking for on an online forum.
Here's how I wired my 2005 Ford Focus ZX3 for trailer lights using a 72" 4-wire hardwire kit from eTrailer.com:
1. Remove the carpet covering the spare tire.
2. Loosen the left side interior molding on the trunk area. There are 4 metal screws (and 1 plastic screw + fastener near the seatbelt area). Note that I left the side towards the front of the car still attached.
3. Remove the plastic molding along the bottom rear of the trunk. There are 4 plastic screws + fasteners.
4. Remove the fastener holding down the left side carpet that's located near the rear.
6. Pull back the carpeting and interior molding, exposing the wiring. You will see 2 push-in connectors. One of the connectors will have a Y connection about 3 inches away from it - one of the bundles will travel along the bottom of the rear of the trunk to the right side taillight and the other bundle will head up the rear of the car to the left taillight
After the Y splits off, you splice the wires as follows:
Use a razor to carefully cut into the black electrical tape around the bundle of wires. Be careful not to damage the wires themselves
7. Using the tap splices that came with your hardwire kit, connect the Left turn signal lead to the predominately light blue wire leading to the left taillight. Connect the Taillight lead to the predominately orange wire leading to the left taillight. Connect the Ground lead to the black wire leading to the left taillight. For the Turn signal, be careful that you're tapping into the light blue wire going to the tail light and not the one going to the trunk light. When you're looking at everything back there it will make sense.
8. Using a tap splice, connect the Right turn signal lead to the predominately light blue wire leading to the right taillight. You can splice it right after the Y splits off towards the right taillight and not have to remove any molding or anything on the right side.
Be sure you completely (but gently) press the tap splice closed with pliers. The metal part of the tap should be flush with the plastic housing.
That's it. I ran the wires under the carpeting in the spare tire area and plan to just leave it hanging out the back of the hatch when I tow my motorcycle. Just put all the carpeting and molding back in place and you're all set.
I don't get it - There is a push-in connector on the Left side of the car - why doesn't someone make a T-connector for it?
The Curt trailer from e-trailer.com went on perfect as well, the drilling of the frame on the right side being the only annoying part. Be sure to torque everything down to 75 lbs. with a torque wrench. It's a lot of torque, and not an amount you can put on with a short-handled wrench.