I have a factory tach in my 85 Monte that's not working. Is there any way I can test it before I send it out for repair. There is power to the back of the tach. Is there something between the tach and the distributor I need to know about? Tried to find a wiring diagram of the tach circuit without success. Can anyone please help?

PS there an integrated clock on the tach that works.

 

Can anyone please help me?

 

I'm not a DIY or tech, but there are smart people here, it just takes time for the right person to see the right posts. Forums are like snail mail LOL
I am confident if given a bit of time you and other person with tach problems will find your best solution