Hello everyone odd problem. Last night I left the ignition key on"run" by accident and this morning the battery was dead and the tac needle was stuck on 7 grand. Charged the battery and started the car tac did not move still on 7 grand. What have I done and how can I fix? 1987 iroc 5.7 with stock tac.
Thanks for any help

 

I don't have a fix for your problem. I'd try disconnecting the battery for grins but I don't know if that will change anything. You may want to do a post in the Electronics Board or have this one moved. The guys that post there may not see the tpi section often.

 

Thanks for the idea. I disconnected the battery then started it up and drove it and the tach works!!!!!!!!!!!!!

 

Excellent. Thanks for reporting it's fixed. So many people ask questions and never let anyone know what fixed it.