I have a very strange problem going on with my 96GT. It warms up in the morning and everything is great and then all of a sudden the temp gauge drops and my heater starts blowing cold air. This lasts for about 5 minutes and then the temp gauge goes back up and the warm air starts to flow again. Possible thermostat problem?

 

its worth a shot. thermostat is like 7 bucks and takes 10 mins to change