2004 Envoy XUV heated seats do not work on both sides. I press the button and the lights come on, when i release the button the lights go out. I checked the fuses mentioned in the articles on this site but still luck. Any help would be grealty appreciated.

SOURCE: fuse

The second fuse panel is under the rear seat.

SOURCE: 2003 Envoy bottom seats not heating up, stopped working same time

I had the same issue with my 2004 XUV on the drivers side. Noticed that a "spot" was hooter than normal right before it quit. The seat heaters are basically a simple wire coil that is laid between the upholstery and the padding. The back and seat units are independent but operate off the same switch. If you are somewhat mechanically inclined, this is not a difficult fix, you just have to be patient and careful. Mine was a year ago and I think the replacement part from GM Parts Direct was less than 50 bucks. The dealer wanted over $300 to fix it. If you want me to walk you thru it let me know.

SOURCE: 2004 Envoy AC works but does not come out the front vents. Only @ windshield

You most likely have a bad mode actuator. http://forums.trailvoy.com/showthread.php?t=40235

SOURCE: 2004 GMC Envoy XUV mid-gate window won't roll up

be sure the gate is fully closed or it will not roll up if it is firmly in place and still does not go up you will have to remove the cover and see if the actuator plastic has broken off from the switch, it also could be a bent rod and or the switch is bad. Check fuses as well just to be sure before going to all the other work to pull cover off. Hope this is helpful and thanks for using Fix-ya.