The drivers side heated seat in my wifes 2002 300M quit working. We live in the Chicago area where it has not been above 10 degrees for 2 weeks. She is complaining that her butt is frozen. I suggested that we move somewhere warm. She said fix it. I have looked for a blown fuse they are all good. The passengers side still works. I took the switch from the passengers side and installed it in the drivers side still no toasty buns. There is power to the switch and power out when the switch is on. where do I check next?

Thanks for any help you can give,

 

9 times out of 10 its the heated seat elemens that brake a line and power can not flow though them ne more. New elements unless thay arnt avalable then haft to get the whole seat foam cover ect.