Im headlong into my VW kit car build and I got a few wires jumbled when I installed the tachometer. The gauge goes from 0-6K, and the needle is currently resting on 6k. After messing with some grounding issues, the tach now powers up but you can hear the motor trying to bring the needle clockwise back to '0' but its hitting an internal mechanical stop. (it needs to come back CCW) So, in a nutshell, my tach seems to have grounded out at 6k and now wont go back. The needle will move with some voltage fluctuations (which tells me its not burned up inside) but I cant figure this out. I even tried reversing the polarity to bring the needle around but that was a no go as well.

Tach signal is negative from coil (but not hooked up to coil yet...Im just plumbing everything in) Hot lead is a keyed source.

Any input to get this thing back to '0' rpm?

 

With no power to the tach, the needle should drop back down to zero. Have you tried rapping on it with your hand or a sledge hammer, or jostle it around if it's not fastened down? Maybe the needle is stuck.

 

You are the only guy Id ever take 'hit it with a sledge hammer' seriously. You know what Im gonna do tonight? Im gonna take it out tonight and hit it with a sledge hammer. Havnt got anything to loose.....

 

make sure you hit it really hard so that you can break it loose lololol

 

heard of the same thing on a gsxr forum. guy knocked his bike over and the tach jumper around and did the same thing. is it an expensive tach? have some sort of personal ties to this tach? if not, spent the $60 for a decent new one

 

Would you believe I tore the glass housing off, turned the dial by hand back to zero and put it back together?....She still shows 400 RPM at a dead standstill but powers up alright and everything else seems fine. Sure, I could spend 60 bucks on a new one but the whole concept of this car is to build it on a shoestring budget using as many surplus, salvage and rebuilt parts as possible. After all, it is just a VW bug and wont ever be worth more than about 1500 bucks.....there isnt much of a way to make it look pretty, so Im concentrating on functional.