I've got an 86 442,The problem I have is if I step on the brake pedal the right rear tail light goes out and the reverse lites come on and I have no right side turn signals and the turn signal indicator lights in the dash are not working also,Left side is okay.I have checked all the bulbs to see if they are the correct ones and the only other thing I've done recently was put in a new gas tank.Any advice would be greatly appreciated to help me get me started in a direction to correct this problem.......THANKS,Rich

 

Did you disconnect or pinch any wiring or grounds when you were doing the gas tank?
SOmetimes it is easy to do without knowing.
The reverse lights are completely isolated from the brake lights, so i sense a pinched harness or such

 

The only wires that were in the area were for the gas gauge and it's working......Rich