Quote Originally Posted by Slade1134 View Post
if was put in after i had replaced the original motor, Ill check the connections when i get home, but if its cold the tack dosnt read correctly , but in the afternoons on my way home it does read correctly. I just dont understand
Sounds to me like you have a very old (like 60's vintage) tach that used an internal "coupling" that can be temperature sensitive. I'd say it may be time for an upgrade?