Temperature gauge does not work on my 1970 340 Duster ?

I haven’t gone back and read the thread again, but is the engine temp really low? I bought one of those infrared thermometer things at harbor freight and t works really well. It was pretty cheap. I think they sell them at Lowe’s now too. You can even take your kids temperature with it by shining it in their ear. Just like a real doctor, almost!
The engine is running at normal temperatures. It is pegged out on the 'cold' setting the whole time.