hopefully you are still under warranty this is a common problem with the crossfires my limited had to have both seats (backs and cushions) replaced around 37,000 mi fortunately had the extended coverage and were replaced at no charge my SRT had to have the cushions replaced around 8000 mi
again with warranty and replaced at no charge contrary to most I have a great Chrysler dealer and while there is a "fix-it" kit available he checked around and found they were not always reliable so he repaired with brand new seats if out of warranty they are real pricy and you might want to try
the fix-it kit or if that didn't work and I didn't have the warranty I would just live with heater and forget the warm seats