Coolant gauge issue

Wilson2608

Thanks for your advice south ark. I have an update that may help trouble shoot the problem as well. When driving the car it stays on the lowest dot, but at idle it will heat up to normal operating temp. Once at that temp my ac stops working.. I'm thinking its a stuck thermostat and I'll check your suggestions as well.
The gas gauge has always been messed up, but it got stuck at half a tank instead of not reading anything

__________________
Stillen G3, z1 Intake Manifold, Stillen Headers, Z1 HFC's, Stillen Catback. 330whp 267 ft- lbs tuned at Z1 motorsports.