[Polygon]

My LeBaron's engine is not holding heat. It heats up but as soon as I turn on my heater the engine temp plummits. Also the temp usually doesn't get to normal. The only thing I can figure is this:

Last weekend my alternator belt snapped and the engine overheated. I was driving home and didn't notice something was wrong until the heater was blowing cold air and when I looked at my temp guage it was almost to the top. So I pulled over and found the belt shredded up. I let it cool down and then drove the rest of the way home. I was just recently able to get the belt back in. All I can figure is that the thermostat is stuck open and just keeps letting water and coolant in.

Does anyone have any other theorys on what may be causing it to not heat up?