1982 ltd 1000

When I apply the brakes, front or back,  speedometer drops to zero.

When I let off the brakes,  speedometer needle resumes.

Turn signal flash slow.  Too much time between flashing.

Battery not charging.

I put a new regulator on.

Undo and clean all you battery and earth connections, obscure faults are normally the result of "corrosive resistance" on the terminals of shared circuits like earth lines