Brake lights on f-350

My 2004 F-350 diesel does not have any brake lights. Fuses and bulbs are good. Any suggestions?

Does the high mount center light work? The side lights run through the multifunction switch, which I've replaced many of, the turn signals might still work, as well as the running lights, but if the middle light works, then it is almost a guaranteed multifunction switch.

Check the switch?

"almost a guaranteed multifunction switch."

What do you mean? I've been out of the business for a while, but I didn't know there were multifunction switches in the brake light system. Wouldn't there be a 'stand-alone' brake light switch and a stand-alone hazard flasher?

Brake lights run through the turn signal( multi-function) switches if it has a dual filament bulb. It could also be the brake light switch since there are 2 circuits coming out of the switch.

Thanx.

You have had to replace a lot of TS switch assemblies for failed brake lights?

As I said, I'm out of the business now, but in over 10 years, I don't think I ever did.