Back seat heat

Just tried the heat controls for the rear seats on the '05 Yukon. Pushing the off/on button will display "OFF" and that is all it will do. The front control is in AUX like the manual says to do. I'm probably missing something simple here. I checked all the fuses that looked like they might have anything to do with HVAC. Any suggestions?

Not sure if this will help or not, but I have a 1999 Yukon Denali and the only way the rear seat heat will work is if the seat belts are fastened.

Not sure if this will help or not, but I have a 1999 Yukon Denali and the only way the rear seat heat will work is if the seat belts are fastened.
Just ran out there and tried it but no luck. That sounds like a trick the General would think of. I'll try it later with someone actually back there and me in the drivers seat. Thanks for the tip.