I have a 1969 mustang conv. Bought it new. Just rebuilt the 302 V8 2 bbl. all of a sudden I have no brake lights, turn signals, radio. Head lights and horn work. I’ve changed all the fuses. What’s the problem? Jeff

 

I’d check the connections of any main wiring harness connections for corrosion.

 

Ok..but which connectors? I did put in a new battery. Could that have fried something?

 

It's hard to say which connectors. But I bet one is loose or corroded somewhere. Hopefully someone with experience on a classic Mustang will chime in. My classic experience is with Corvairs, not Mustangs.

 

check the connection at the fire wall.

 

Did you detail the engine bay before you reinstalled your engine? If so and if you painted anything in the engine bay maybe when you reconnected your ground wires the paint will keep from making a metal to metal connection. Scuff with some sand paper around the hole and should have a better connection. ( i have done that with several of my resto projects).