factory tach problems

[Budget78]

I have a 75 gage cluster with a factory 75 tach. It worked before I tore the truck apart but when I put it back together it doesn't work. I have an accel HeI coil with 1 wire coming out of the tach side of the coil, going into the factory tach. Is there more to it than that?

Thanks in advance

[Captkaos]

That should do it, but some 75's had a buffer in them.

[Budget78]

could you explain BUFFER please. Im thinkin its like afuse being that on this i found out on some of the guys posts that it would be an AMP style tach. The other thing i noticed is that there is no signs of to much heat or power damage LOOKING at the back of the tach . I like the original tach but if it cant be fixed is there any after market tachs that would be able to fit in its place in the bezel. THANKS IN ADVANCE AGAIN.                         THANKS JAKE

[Armor]

my factory tach worked great until one day i took the cluster out to get behind it and put in the dash speaker, put it all back in and tach was pooched. It sucked but from what ive heard they are pretty finicky and are prone to breaking. Hope it still works!

[Wardog]

If you haven't figured it out yet, check your connections to your tach.  You have 12 vdc that is supplied from the fuse panel; a ground, plus the signal from your distributer.  If the needle won't move when you turn the ignition on then it may be the 12vdc/ground.  Good luck!