You probably have a burnt fuse-link, or a bad horn relay terminal. You heard me right....horn relay.
On the older Sharks('68-'73), the battery voltage goes from the center terminal of the starter solenoid to the horn relay, on the driver side inner fenderwell. From that point, there are several terminals on the horn relay that "distribute" the battery voltage to the rest of the vehicle. There should also be a couple of fuse links comming off of the horn relay wiring to the inside of the car.
I would first check all of the terminals on the horn relay for power, and then check the fuse-links for power on both sides of the links.
A bad fuse link, or a damaged horn relay terminal will pretty much kill just about everything on the car, depending on what wire/circuit is dead at that point.
hth

Boy, this Joel guy sure knows his stuff !!  I was just about to write the same thing!!  lol

Joel - Im speechless

[QUOTE=KeBo]Joel - Im speechless[/QUOTE]

That's a FIRST!


I throw out whatever info/ideas I may have at the time...some might even be sorta on target...sometimes...

Hi Joel: You may have solved a problem I am having with my '73! Thanks a bunch. I am getting voltage to all the right places, except I have not checked the solinoid lead off the starter. The battery leads are getting voltage (black and red leads). I will try your solutiion this afternoon.

What color is your C-3. My '73 is 2003 Anniversary Red Tri-Coat. Lives in San Antonio.

HH

Hope it helps!
My '74 is the original color, 74L, Medium Red Metallic.
Adams' Apple2009-12-27 19:31:11