It is a 1992 f350 4x4 460 5spd CC all lights work, hazard, left and right turn signal just no brake lights. There is power to the switch at the pedal and out when pushed.
Any suggestions before i start chasing a lot of what ifs?

It has a tekonsha brake controller.

 

Do the brake lights work if you manually activate the brake switch?

 

No brake lights on the truck when I slide the trailer controller also no power to the 7 way plug brake light port.

 

Check where they tied the brake control to the brake light circuit. Maybe bad connection. Or possibly bad turn signal switch, brake switch feeds ts sw then to brake lights.

 

On my expedition it was the brake switch on the pedal, I took it apart cleaned it up and put a spacer in it and has worked for the last year

 

I get power on the out side when I press the pedal so it is good. I'll trace some wires today.

 

Does the center stop light in the cab roof work?

 

no third brake light...

 

D'OH, I thought the center stop light started in '92; sorry.

It could be the multifunction switch. The brake light circuit goes through that switch. When the turn signals are in the OFF (neutral) position, there are contacts that are closed that feed from the brake pedal to each of the lights in the bed. When you engage one direction, or turn on the emergencies, that set of contacts opens and the contacts from the turn or emergency flasher feed the appropriate circuit to the lights. So the break would be at the switch connector, the switch contacts, or possibly the wire between the brake pedal and the switch.

Reason I asked about the center stop light is, the circuit for that light goes right from the pedal switch to the light socket, it does NOT pass through the MF switch. When that light works, that further suggests a MF switch issue.