Re: Tail lights not working. 1972
There is no reason to replace all the bulbs, just remove them and clean the sockets. The horn/s are powered by a relay that is looking for a ground supplied from the black wire fed from the horn button. The relay has 12v on it at all times and once it gets a ground signal it provides 12v to the horns. So you need to see which half of the circuit is not working, the ground side or the plus side.
You're just jealous because you can't hear the voices!
1967 Olds Cutlass 468 BBC/T400
1963 Plymouth Fury 440/Torqueflite
2007 Ford Mustang GT (momma's car)