Replaced Tach, still reading high, do I need a TACH FILTER installed? And where does it go?

[azmusclecar]

Odd thing is, I removed my dash, managed to get all the gauges working, I put the gauge cluster in without fastners and the tach reads correct.
It zeros out at key on and the idle rpm is right and a few blips of the throttle and the tach reads and returns as it should.

I fasten the gauge cluster in and start the car and the tach begins to add rpms as the original one did. So, would a TACH FILTER
help? I've never used nor even knew of such a device but it seems I am out of ideas.........and for less than $10 is it worthwhile to
buy and install or do my problems lie elsewhere?

This is the part I am considering...........thoughts and ideas please................

GlowShift Gauges, LLC - Shopping Cart

GlowShift Gauges offers a complete line of performance automotive aftermarket products, including a variety of gauges and gauge pods for any vehicle.

www.glowshiftdirect.com

 

[fleming442]

Tachometer Filter-2697

www.mikesmontes.com

It sounds like something is shorting to ground when you install the cluster.

 

[azmusclecar]

Tachometer Filter-2697

www.mikesmontes.com

It sounds like something is shorting to ground when you install the cluster.

Thanks for link.........I'll consider this one as well.............

 

[Gonzo1970]

When I required a tach filter, my tach was Jumping around... not just reading High. This was from the HEI Ignition System, and that glowshift filter did the trick for me..

Strictly reading high tho, I seem to recall a thread here about that in Chevy's when I was having my issue, but his was just reading high, not a jumpy tach, so I moved on.

-Gonz

 

[azmusclecar]

Yes it's not jumping liek with voltage spikes........it just doesn't keep accurate rpms..........
I soldered a jump wire on one tach and then I used one of the OE spring clips on the other
and both tachs do the same thing. If the cluster is just setting in the pod hole, the tach works.
Fasten it and the tach reads faster than what it should.........I cleaned all contacts and posts
and strips of copper, unless it is something in the circuit board I am stumped................