There are two scenarios in which you’ll have a AutoMeter gauge thats not accurate or is not set to zero when the car is turned off.
1) You received a brand new Autometer gauge
2) You’ve had a gauge for a while and it is inaccurate, or it shows -5 or +4 when the car is turned off
Now, if you have a brand new gauge, Autometer frequently ships the gauge with a locking pin in the back of the gauge that needs to be removed and the gauge will be good.
Now if you have installed the gauge and it was fine, but then its now inaccurate, you will need to send it to Autometer for calibration. Auto Meter
Attn Service
413 West Elm Street
Sycamore IL 60178
Autometer’s service form is located at:
http://www.autometer.com/media/Service_Form.pdf
Autometer’s phone number:
866.248.6356