SOLVED: Fuse for heated seat 2004 GMC Envoy - Fixya Dec 12, 2016Fuse for heated seat 2004 GMC Envoy. Owners manual does not list location of this fuse Posted by Both heated seats in my 2004 envoy went out at the same time. should be a fuse in the fuse box. check all fuses and wiring. with the bumpy roads even one wire from eaither seat was to come off both would stop operating. Jan 11, 2011 2004 GMC Envoy Power & Heated Seat Components - CARiD GMC Envoy 2004, 2 Series™ Copper Wire Seat Heater System by Heat Your Seat®. Location: 1st Row. With Round High/Low Rocker Switch. The Universal - Parallel Wired Seat Heater Model with the Round High/Low Rocker Switch is a single seat..