heated seats stopeed working in mY 2004 Grand Marquis!
 

Its freezing here in PA and my dam heated seats wont work. They dont work on the driver or passenger side. The lite comes on when you press the button but no heat. Help Me, my butts cold! Since both sides do not work I assume there is a switch or control module somewhere thats bad. Thanks!

Start checking the fuse box in the pass. compartment and the "power distribution" box under the hood......Your owners manual with have a menu of the fuse positions and what they serve, start there.

I'm with Dave here. Start with the fuses and work from there. It would be strange and coincidental for both elements to go out at the same time, although it happened in my truck a couple of years ago.