GMC Yukon XL Denali Heating and AC Temperature and Air Delivery Mode Door Actuators May Fail

AC onm, blows heat on drivers side and cold everwhere else.

A/C blows cold on driver while pass gets heat... sometimes reverses in the winter. With or without a/c.

While my a/c is running, for no apparent reason the heater will kick on full blast. And just within
the last few months when this occurs, at the same time, my seat heater on the driver side will
mysteriously turn on High. When I realize that my seat is blazing hot & try to turn
off the seat heater, it continues to turn right back on like 6-10 times in a row...every time I turn it
off, within 1-2 minutes it turns right back on! This is NO Fun to deal with while I am driving in traffic or on the highway, especially when it's well over 100* outside!! Any possible explanation would be greatly appreciated! Thank you

No heat on drivers side, only blows cold air. Everywhere else heat is on.

Air direction for front heat/cool fan only blows windshield defrost, unless dial is turned to defrost in which case it blows less on defrost and gives you a little air from the foot vents; rear blowers work fine.