I have a 1960 C-10 Fleetside. I need help figuring out how to wire the turn signal/stop lights. The tail lights are fairly simple. Those are working properly. I have three wires leaving the cab. Black is tail lights. Simple. Red and green I think are the stop lights and turn signals. With the passenger side turn signal on, I have power in the green wire at the cab. Same for driver's side with the red wire. When the brakes are applied I have power in both wires and both stop lights function. It gets weird after that. When the drivers side turn signal is actuated, both sides blink. When the passenger side signal is actuated I get nothing. Long story short. I need help with a simple diagram how the turn/stop wires are connected. I will be cleaning the rust/paint etc. from where the light housing connect to the bed and replacing all wires. I've replaced the sockets for the tail lights. The bulbs are new also.

Thanks in advance.