My taillightts aren't coming on when I turn on the headlights. The brake lights and turn signals in back are working fine. I pulled the taillight bulbs and had them tested, and they are fine. I'm thinking I just need a fuse diagram for the car so I can check the fuses under the sterring area.

could be a faulty globe too

Change the bulb. When you press the pedal the brake switch changes the circuit to the 21w brighter circuit for the brake light.

Did you check the front also for a broken wire? It's the park light circuit, so it may be a short at rear or front of car.

no, sorry . but i do have a suggestion that might help. do the taillights work? if so check the brake light switch on the brake pedal. also , does the high mount light work and not the rear ones? if so you may want to check the turn signal switch to make sure there is voltage on that circuit.

check wireing may be wired wrong them head lights may not be compatable with that setup

Those lights are called running lights. Have you tried new bulbs or test the wires coming into the socket for power.

Some fords have fuses for taillights, check there too.

Sounds like you 've got a cross connection in the rear right taillight bulb, or wiring to that area.
Start by pulling the bulbs out and checking if it makes any difference with the bulb removed. Check the brake pedal...see if the parking lights still come on.
Look at the bulb socket contacts, and the bulb contacts and look for black marks, or burned out filament in the bulb.. if everything looks good there, start tracing the wiring back and look for cuts or a place where the wiring may have been pinched, cut, bared etc. if your right turn signal isn't working and the parking lites are getting triggered, it's got to be in that right rear taillight or wiring...

sounds like a faulty underhood fuseblock..have seen lighting issues with these components

First, let me say that the wooden boxes are a mistery. Have not got a clue.

As for the brake lights. If the lights work with the headlights on and the directional signals work, then look for the switch not working. It is usually located directly over the brake pedal, but farther up inside the dash.
Sometimes the directional signal can cause the same thing. The brake light system runs throught the directional signal system. This is how you can have on light flashing while the other is solid red, when braking with the signal on.

check all your fuses