Does anybody know how to calibrate the temp gauge without a scanner?

[corsagtp]

I put a gauge overlay on and accurately put the needles back on the gas, tachometer, and speedo gauges but the temp gauge is off. I can’t remember where the temp gauge was when I took the needle off. (I thought I took a pic to mark it but I guess I forgot) Does anyone know where the temp gauge needle should be with the ignition on without the car started and the motor completely cold?

This is where the temp gauge is now with the ignition on and motor cold

 

[97gtsc]

Right at 0 or _ / # were it starts

 

[minichopper6hp]

Youre gonna need a scanner.

 

[corsagtp]

I was hoping there was a way to get it accurately without having to spend money on a scanner