98 F-250 passenger brake/signal light

My park light works on the rear passenger side but there is no flasher or brake. The reverse lights work. I can't figure it out. Any Ideas?

Bad bulb. There are TWO "lights" in one bulb. One: parking (tail) light, the other is the Brake/Turn (same unless you have amber turns). If the Brake/Turn filiment goes bad, neither the brake or turn light will work.

there is no power coming from the main harness to either the brake or signal wires. bought new bulb but there is no power coming to the connector. Maybe a fuse but I checked them all. how do you tell if a relay is working?

I don't think there is a relay for the vehicle's brake lights, only for the trailer harness.

You might have a bad Turn Signal switch if the Right stop/turn lights work ok, because the brake lights "go thru" the turn switch first.