Erratic Tachometer help

[cbrown91]

Alright, my tachometer keeps going from the correct rpm's to about 1,000 over and back down in a couple minutes time.
I have checked the grounds.
I also hooked up a basic tachometer, to the test connecter for the tach signal, and the basic tachometer was reading the correct rpm's, while mine was going up and then back down.

Would this mean that my tach in my instrument cluster is the problem?

Any help on this would be great.

 

[itwonder]

Mine has been intermittent for a long time. It drops to zero, not 1000 when it dies though. I got a cluster a while back and will swap it one of these days when I have time. I traced the wire from the DIS to the tach and didn't find any problem, so next step is the cluster. Post in the WTB section. They are not too difficult to find.

 

[cbrown91]

Sorry I wasn't clear on this,

the tachometer will go up around 1,000 rpm's over what the actual rpm's are.
In about 1-2 minutes it will drop back down but then go back up.