Tachometer intermittently working...

[djidentity]

So, when I start my engine my tach registers at 0 and kinda bounces a cm or more till I put it in drive. After that it will either stay at 0, or it will register at the appropriate rpm for a while, then just kinda bounce around. After a long drive, it will go all the way up as far as it can possibly go before hitting the pin and then going back to hang out at 0 again.My engine still runs as perfect as it always has, and I am having no idling problems or anything.I have no clue whats happened. Im assuming there is an electrical issue somewhere but I completly suck when it comes to electrical. KA motor incase anyone asks.

No clue where to start... anyone have any ideas?

[Ni$$@n240]

Im no expert but since it runs fine it wouldnt be the sensor. I would go with a different cluster or just check the connector for the cluster.