hi i got a tach problem, the thing just recently started to wave around like its on crack.. for like no reason at all.. any idea whats causin it and what kinda solutions to help?

 

I dont know if this will help or not :shrug: but mine was doing that not to long ago and it did it even worse when i turned the right blinker on. from time to time it would go away but it would come back and start happening again. I started to get into the gauges thinkin that this was the problem and found that there was a short in the connections that go into the back of the cluster.

 

well its just been doing that problem on a steady basis. i dont think it really mattered what signal i used. but thanx for the help anyway d00d

 

The tach in my 85 floats around all the time. or it will spin all the way around and goes passed the redline and stays there.

 

I had a tach that did that when the vehicle was started. Checked the wiring from tip to end. Eventually brought it to Chevy and they said they could fix it for about $300 and it would take 4-6 weeks and they would keep my car. I ended up buying a cluster for $20 on ebay. Works great.