I've been having some temp/heater issues with my 07 Dodge Grand Caravan and wanted to run it by the folks here. first, if I just run the A/C I don't seem to have any issues. But if I turn the heater on, it blows cold for awhile. Then there is a temperature spike before it settles back down to normal and then it starts blowing heat consistently. If I turn the car off but come back before the car cools too much, the heater will still work. but if the car sits and cools too much, it does the same temp spike, settle, then works. Now, I've been thinking the thermostat is going. And I like this because it's a pretty darn easy fix on my van. But there's something else. Of course. There is a whining sound, like a pulley going, from the front driver's side. Which, of course, could be connected to the heating issues. Or it could not be connected to them at all. I'm tempted to just take it to the mechanic because I don't feel like hassling with anything serious, or just replacing the thermostat and seeing what happens (it's a twenty dollar part and a thirty minute fix, so it's not a huge investment). Any takes on this?