I installed a new tach on my 69 Z/28 from Rick's, with a new instrument panel. I haven't insalled console yet, but all electical seems to be working except tach. I have a flamethrower distributor on it, new interior wiring harness (from fuse block back) and a new front wiring harness (fuse block forward). I believe that it was working before I removed everything. Anyone have any ideas on how to check the problem? Short of removing the tach that I spend too many hours installing? Thanks very much - p.s. I have searched old posts, but I haven't found this particular issue.

It should be connected to the -negative side of the coil....

Thanks Skip - I'll check it out. Nice car!