Hey guys - I'm stumped. When I purchased my '68 Bird, it had a hood tach installed, but no harness to hook it up with. I purchased a harness, hooked it up, and all I got was lights. No rpm reading. I assumed that the tach was bad and purchased a reproduction one. Hooked that up, and all I get is lights again.

Here's how I have it hooked up:
Black wire to ground
Black w/ pink wire to negative side of coil
Gray wire to Acc Ign on interior fuse box

I have also tried to hook up the gray wire to the lamps receptacle on the fuse box.

What is wrong? Is there something wrong with my coil? Do I just have it hooked up wrong??????