I put an HEI distributor in my Olds 350 a couple months ago. I disconnected the tach wire from the original coil and connected it to the TACH connection in the HEI cap, but my tach doesn't work now. What do I have to do to make it work?

 

Re check connections B+, tach & ground 4th wire for light on aftermarket units ,no reason it shouldent work ,factory tach should just have 1 comming in engine harness