need help! when i connect tach wire (white at coil) , engine will not fire.
has new module,rotor & cap . coil is ok.

is it possible there is a filter or some kind of electronic module behind the cluster?

tried aftermarket tach at the coil , it worked fine,also another oem tach which did not worked ,installed in cluster

1989 iroc z28 (had two months)
l98 350 tpi
7000 tach

thanks

 

There is no filter behind the cluster.

There is one (supposed to be anyway) on the firewall right behind the distributor.

Either the filter is bad, the wiring is bad, or your tach is bad.

It's extremely easy to remove the instrument cluter from teh dash, as you probably already know; if you can remove the cluster and the problem goes away, it's the tach. If you remove the cluster and it still has the problem, then it's the filter or the wiring.

 

will check with your suggestion today.

thanks RB8369

 

located problem: it was in wiring between coil and firewall (driver side).( dead short).

repaired wire & connected tach wire , crank her up . then she fired with tach connected.

also tach works.

thanks RB83L69

 

Easy enough.

Glad you got it going!!