Possible Causes

WARNING: This page is about a different car, the 2004 Mercury Monterey and 2004 Ford Freestar. However, it is still accessible from the selected car via links, so may be relevant.

An inoperative heated seat can be caused by:

open fuse.
wiring, terminals, or connectors.
a faulted heated seat element.
a faulted heated seat module.
a faulted DATC module.