Found more info from another owner for you. Rather complete instructions too:
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"If you are in the minority of TBird owners that wants to pull a small trailer behind your TBird, you have some special challenges for the hitch and lights.
Take note of this first:
1) The hitch I used is Class I rated for 200 lb tongue load and 2,000 lb trailer however I would not expect anyone to try and tow anything near that weight with a TBird. Although Ford initially offered a trailer light tow kit for the 02 models, I do not think Ford endorses trailer towing any longer. Even when they did, I doubt it was for anything more that 1000 lb. Although I have a very small trailer I use occasionally for bulky items, I will never exceed 1000 lb. My primary use of the hitch is to mount a bicycle rack.
2) Hitch requires cutting a notch in rear bumper fascia
3) Trailer lighting is not straight forward and requires a special kit as explained below
Hitch - DrawTite used to list a 1¼” hitch for our birds but it is no longer found on the DrawTite web site. However, the same hitch is still available from U-Haul as
part number 24705 (same as used by DrawTite) for $117. The hitch can also be found on other web sites but at a considerably higher price. The data sheet that comes with it is a DrawTite drawing. Installation requires you to drill 4ea half inch holes in the aluminum frame. It also requires you to cut a 3 X 1 1/4" notch in the lower center of the bumper fascia. I have installed hitches like these many times in the past but in my old age I got lazy and had U-Haul do it for $30. Fishing those bolts thru the frame is easy if you have the right tools but it is a major PITA if you don’t have them. (Note - the hitch is steel and our frame is aluminum. That sets the stage for galvanic corrosion if not installed properly. Be sure to use isolator shields (included with hitch) where the hitch makes contact with the frame.)
After installation, the receiver portion is the only
part of the hitch that can be seen. It is not highly visible on a black vehicle like I have but it can easily seen if you are looking for it.
Trailer lights - Our TBirds use method called "low side switching" to control all the electrical items including the exterior lights. This approach is not real common but it has been used on some other vehicles from Ford. In this approach, the wires to the lights are always hot and the lights are activated via one of the electronic modules grounding the circuit internally in the electronic module to complete the circuit. This approach also allows the system to monitors the lights so the computer can tell you when a light has burned out because that event changes the circuit as seen by the computer.
This means we cannot use the old fashion method to just tap into our light wires and drive the trailer lights directly. Although some enterprising individuals have managed to devise their own circuitry to deal with this, that approach is not viable for most people. Fortunately, enough vehicles have used low side switching such that a kit has been designed to deal with this situation. The kit is called "Plug-N-Tow (TM) Low-Side Switching Hardwire Kit" (
part number 36345). I got mine from etrailer.com and it sells for $59.59 + S&H. I do not know if it is available elsewhere or not. The kit has a small black box that monitors the car lights and uses that as triggers to activate the trailer lights which are powered directly from the battery…not the TBird lights.
I did the wiring myself. I have heard that U-Haul installers have been told not mess with TBird wiring but I intended to do this myself anyway because I do not want someone else experimenting with my electronics. Since the kit is designed for multiple vehicles, it did not hook up perfectly per the instruction and I had to do some experimentation to get the right combination of wires hooked up. This is what worked on my 03.
First, you will need to remove the tire cover, right side trunk liner and the cover shield that covers the trunk latch. You only need to do the last step if you choose to ground the kit at same location I did. If you ground it at the battery, this last step can be omitted.
Second, locate the wires noted below for connection. (Note – depending on where you look in the wire looms, you may find multiple wires with the same color combination.) I tapped in where all the wires run together near the battery. I had to probe with a volt meter and pin (to puncture wire cover) to find the wire I was looking for. Once found, I preferred avoid cutting the wires so I scraped away enough insulation to attach the new wire on and solder it. In hindsight, I should have connected at the point near the right rear taillight where the wire loom splits and runs across the rear of the trunk. That should avoid some of the probing for the correct wire. Hint…before I started soldering wires, I hooked up all my wire (no solder) and tested my trailer lights to make sure everything worked correctly.
Wiring the kit - You have 6 wires to deal with as follow. The kit also includes some crimp on wire connectors but they are trouble in the long haul so do not use them. Crimp-on connectors will oxidize over time and the connection will go bad. Solder the connections for long term reliability.
Big Red wire – connects to positive battery terminal. Kit includes an inline 20
Amp fuse but I felt like that was too high so I swapped in a 15
Amp fuse.
White wire – connects to ground. I used the grounding attach point on the body near the trunk latch. Could also connect at the battery or where the battery hooks to the frame ground. I chose not to do that because that (1) kills all power to vehicle and (2) disconnecting the battery ground connection to the frame generates sparks and I do not like power surges running thru my electrical components..
Small red wire – No connection (cap off). This is different from the instructions. This wire is designed to read the brake signal on some vehicles. In a system where the brake bulb is a standalone bulb, this connects to that bulbs wiring. In a system that has brake/turn/etc all in one bulb (our TBird), this wire is supposed to be grounded along with the white wire. However, when I did that, the brakes worked in reverse (brake on =
brake light off, brake off =
brake light on). I tried hooking the red wire to the wire that feeds the top center
brake light and there was no reaction at all in the trailer lights. I disconnected this red wire (no connection at all) and discovered that everything worked correctly. This approach (no connection) was not offered in the instructions and I cannot explain why it works…but it does. I suppose it is
part of the mystery of how the low side switching system works.
Green (Right Rear) – connects to the BK/GN wire that feeds pin #3 on the right rear tail light
Yellow (Left Rear) – connects to the BK/OR wire that feeds pin #3 on the left rear tail light
Brown (tail lights) – Connects to any wire that activates an exterior light when lights are on. I connected to the BK/OR that feed pin #2 on right rear tail light."
