POTATO!?!?

Well, I heard once that jewelers rouge and a polishing wheel on a drill will buff out light scratches, and also that TOOTHPASTE will work too (plain old CREST). Needless to say I looked like an idiot smearing jewelers rouge and then toothpaste on my windshield and buffing with that wheel to get ....no results. Get a new windshield if it bothers you. Enjoy watching the glass guys replace it, and do something with your kids/grandkids with the time you saved by not doing some half-assed fix to try to save a few bucks.

Seat heater switch: Might be the switch. They sit in a bad spot and get all crudded up with all sorts of dust and grit that settle in that part of the console. If you don't want to buy a new one needlessly swap the one that works with the one that doesn't. If it still don't work than I would check the thermostat wiring and connections.