2003 GMC Yukon XL 1500 Q&A
2003 GMC Yukon XL 1500 Question: Why does a/c blow hot air on driver side only?
there are blend doors that control this,poss bad blend door on d/s or circuit issue( controller) - globalhelper
low refrigerant charge, the computer cannot keep the whole vehicle cold with the charge in the system, but its pretty smart, so when the refrigerant pressure goes below a certain value, it tries only to keep the driver of the vehicle comfortable. so the refrigerant system has a leak and its low on refrigerant. - Dealer Diagnostics