90 vette tach, not working?
Thread Starter
Advanced
Joined: Mar 2009
Posts: 67
Likes: 0
90 vette tach, not working?
on my 90, my tach is not working, it seems the other gauges are.
What could be the issue?
when the car is started the tach moves ever so slightly, then just doesnt respond.
Any opinions?
What could be the issue?
when the car is started the tach moves ever so slightly, then just doesnt respond.
Any opinions?
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
Check the white wire on the distributor to be sure that it is fully connected/seated.
Check, clean, reseat the wiring harness connector at the back of the cluster.
Tach filter (mounted on the back to the tranny on the upper bell housing) might be bad or busted.
Cluster may have issues.
Check, clean, reseat the wiring harness connector at the back of the cluster.
Tach filter (mounted on the back to the tranny on the upper bell housing) might be bad or busted.
Cluster may have issues.
Safety Car
Joined: Mar 2005
Posts: 4,723
Likes: 11
From: Winnipeg Manitoba, Canada
same with mine. A faulty tach is very common on a 90. You can try a new tach filter, but they rarely solve the issue. You can also send out your cluster for repair but its costly. My advice would be to find a newer cluster and just replace it. I bought a cluster from a 1992 off of a forum member a few years ago. It's been working great ever since.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Instructor
Joined: Jul 2020
Posts: 196
Likes: 14
From: Houston Texas
Tach filter, 1990 C4
same with mine. A faulty tach is very common on a 90. You can try a new tach filter, but they rarely solve the issue. You can also send out your cluster for repair but its costly.My advice would be to find a newer cluster and just replace it. I bought a cluster from a 1992 off of a forum member a few years ago. It's been working great ever since.
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Instructor
Joined: Aug 2018
Posts: 168
Likes: 22
From: New York
This thread is over 15 years old. 90’s don’t have a tach filter. What goes bad and makes the tach read incorrectly is the analog calibration IC.
Check out the website batee.com. He gets high marks for repairing these units.
Check out the website batee.com. He gets high marks for repairing these units.
Burning Brakes
Joined: Sep 1999
Posts: 786
Likes: 31
Cruise-In II Veteran
My 1990 convertible has a tach filter. Had to replace it a few years ago with one bought off the "auction site". It is a PITA to get to it as the clearance between the firewall and the engine is marginal. Hard to get my hands in there.
Instructor
Joined: Aug 2018
Posts: 168
Likes: 22
From: New York
My tach was always pegged high. I bought an IC from batee and changed it myself. Problem solved. As hard as I looked I could never find a tach filter. Don’t think there was one indicated in the 8A section either but I don’t remember and no longer have the 8A.
Team Owner
Joined: Sep 2003
Posts: 25,388
Likes: 2,741
regarding the poster 'altownsend' who mentioned looking for/WTB, why? Is it missing, has obvious damage to the wiring from the distributor to C100 or actually diagnosed as being faulty? It is likely NOT responsible for a tachometer error.
Instructor
Joined: Jul 2024
Posts: 153
Likes: 52
From: Northridge, CA
Corvette Central has new tach filters listed on thier website.
https://www.corvettecentral.com/c4-8...-filter-393125
https://www.corvettecentral.com/c4-8...-filter-393125
