i have a 1990 camaro rs, v6, 3.1L. When my car is runnning or off my tacho sits the opposite way its supposed to. wen i start my car it moves to 2000 or something, then goes back the wrong way. All fuses are fine.

 

this is a common issue in the 90-92 cars. there is a resistor on the tach board that can be changed. do a search on the subject you will turn up alot of info. i have stumbled across one post that actuallt told you what size resistor to use and where it goes to fix the issue. or you can go the route i went and put a nordskog digital dash in.