Autometer gauge is pegged out above 250 temp reading

I was driving my 1970 Charger RT today and my autometer phantom electric water temp gauge was pegging out above 250. I pulled into a parking lot,turned the car off and waited for about 10 or 15 minutes thinking it was overheating. The top radiator hose was not stiff with pressure.

I cautiously took the radiator cap off after using the pressure release lever and nothing happened. The car was not overheating at all and barely had any extra coolant in my catch can. I turned the key on but the gauge stayed pegged all the way past 250.

I then drove home,turned the car off,went inside for a couple of hours and went back out the garage turned the key on and the gauge was still stuck. I took the wire off the sending unit and the gauge is still stuck when I turn the car on again.

The car has never ever overheated before. I am guessing that the gauge suddenly went bad?

take the wire off of the gauge as it might be grounded somewhere, otherwise yes it sure sounds like the gauge went belly up.

Yep I think it did as well. The water temp gauge has the same ground as all the rest of my gauges and they all work fine and have for years and year.

I put a multimeter on the wire leading to the sensor and it had voltage to it with the ignition in the ON position. I grounded that wire just to see what it would do at the gauge and it did absolutely nothing. LOL!!!

I will get a new gauge. Thanks!

when the time comes post if the gauge was it.

Yep.

If the wire becomes grounded it will peg the gauge

Welcome to the wonderful world of accurate Autometer race gauges
AKA aside I
I've seen more than one expensive race Autometer gauge read very inaccurate