I was driving the R back from Florida to Indiana, and in Florida the temp gauge for the coolant was where it was supposed to be "in the middle more towads the cold side". As we were heading North, it started to drop and eventually it was at C the whole time. If we pulled over and didn't turn the car off, it would go back to the middle. Heat worked the whole time. Is my thermostat bad?? Hopefully I gave enough info to you guys, so tell me what you think.

 

sounds like your thermostat is stuck open. Time to replace it...

 

What cheezthis said.