Taillights and turn signal lights don't work - 2004 Ford F150

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

YOU MIGHT HAVE A BURNT OUT RELAY IN FUSE COMPART UNDER YOU CARS HOOD CHECK THAT OUT THRU YOUR CARS MANUAL,IT WILL SHOW YOU WHICH RELAY IT IS?

If you are not getting power from the headlight switch for that circuit, but the other side works, you'll have to trace the wiring. The socket has two wires plus a ground. One wire is for the tail lamp circuit and the other is for brake-turn signal.

The only thing left is the wires and the bulb socket. The problem has to be there.

yes they run off of seperate fuse in fuse box. as always check the bulbs first.

Yes. But do you have seperate yellow turn signal lights in the rear or do the turn signals work independant of the brake lights? If yes then you need to wire in a taillight converter. It takes your seperate left & right turn signals combines them with your brake lights on 2 wires instead of 3 leaving you with your normal 4 wires in total instead of 5. 1 Left turn & brake light. 1 Right turn & brake. 1 Taillight. 1 Ground. = 4 wires in total. If you dont have seperate rear turn signals just find left turn wire in taillight assembly, Right turn wire & Taillight & a good ground & you are done. On trailer plug yellow is left, green is right ,brown is tailight & white is ground.

They are different bulbs man!

check connections and fuse for taillights

check all your fuses

I had the same problem with my 1996 Mystique about a year ago. The brake and tail lights stopped working, except for the center brake light in the window. Turned out to be oxidation of the terminals at the connector on the turn signal. Yes, that's right, turn signal. The electrical signal to the tail lights goes thru the connector on the turn signal. To fix, I cleaned the contacts and the brake lights started working again. Hope this helps. Cheers, Henry