My rear passenger side brake light doesn’t work on my 73 chevelle Malibu. I’ve tried tracing the wire as well as verifying power which it has. The socket is fed in series from the brake light on the other side that works just fine. Any ideas on what the problem might be.

 

If the car has the factory wiring, the feed comes from the turn signal switch. The same part of the bulb serves as the turn signal as well as the brake light. You said there is power there? Make sure the bulb is good and makes good contact in the socket.