1977 pickup tail lights break lights work step on break rear right lights go out???? Have replaced the bulbs and break light switch cleaned grounds checked for corroded tubes

 

A problem well-stated is almost solved... Please put us next to your truck so we can help troubleshoot from thousands of miles away.

1) ALL rear lights go out? or
2) BRAKE lights come on but all TAIL lights go out?

What happens when you use left turn signal?
What happens when you use right turn signal?
What happens when you use hazards?
How did you clean grounds? how clean did you get them? Where are the grounds?

Double-check your connections, light sockets, wiring. Connections should be bare, shiny metal making tight contact with bare, shiny metal. Anything short of that is no good.