I replaced one of the heating elements in the seat cushion on the drivers side, and that made no difference. According to two dealers I need to replace the whole seat cushion - there are no other fixes availabe - about $400 for a new cushion assembly.
I know that somewhere on here there is a write-up from somebody who replaced the whole heating pad with an aftermarket piece - anybody know who wrote it, or where it is? - I've searched and searched.
I may attempt to bypass the element that's not working and cut it out of the loop altogether - I think the elements are wired in serial so I should be able to do this. Hopefully it's one of the side bolster pads and not the main center piece.