When the ac is on the driver side vent blow only hot air and the passenger vent blow the cold ac air

SOURCE: no heat of drivers side blows cold air while

Replace the door blend actuator behind glove box, approx $150 for part, Everyone I know with dual control on the silverado's have this problem.

SOURCE: 2004 GMC Yukon blows hot air out of the driver

Probably the left temp actuator. The wires in the right I/P junction block could have poor tension also, but it's usually the temp actuator.

SOURCE: Ac bows hot air on high when on auto- only on the drivers side

the vent channels behind your dash is where the problem lies. It mostly depends on you and your skill. You are going to have to get help also because the dash lifts up and rolls back twards the driver and passanger seats. what you have to do is first check the cable or vacume assembly that operates the vent controlls, make sure nothing is disconnected or broken. If all the cables are in place and move correctly and the vacume hoses have all been pulled off and checked for crackes wholes and functionallitgy. then start checking the seals and vents that route the air flow. find the one that goes to the driver side make it move with your hands then see where the movement comes from also check the seals if they are broken or have come off and are just not allowing air to be channeled to that location. Also make sure that if the control pannel in the dash board is good. Usually if its electric and bad there is a specific smell you will get from burnt electrical boards or components.

Taking a dash off is not the easiest work in the world, and you have to remember wheere every single screw, bolt, nut and clip goes. If you forget one single thing the dash could ratle squeak or do something that will totaly drive You INSANE for the rest of your life. I am not trying to say don't do it, I love DIY'ers but think about if your ready for this. Is your skill where it needs to be and do you have the tools needed for this task. Also, I would buy a Chilton, it will have ilistrated pictures and special notes. I hate saying this also but read the entire procedure first before starting I once took the entire dash off of a chevy blazer to replace the heater core just to find out I had to cut a molded plasitc shield under the hood. Had to put the entire dash back together without replacing the heater core because I didn't have a cutting device for the plastic shield.

Hope this helps

Tepfy

SOURCE: ac blowing hot air on passenger side only

If you only need the A/C to work (at least for now) on the passenger side, remove the panel from below the glovebox. It requires, I think, a 7 or 8 mm socket. Once this is down you will see a little white, plastic arm hooked to a threaded, metal shaft. Manually push the shaft and plastic arm toward the driver's side of the vehicle and cold air (if the system is, in fact working properly) will miraculously come from the passenger side.
You can take a plastic tie-wrap and secure the arm in this position as long as is desired in order to obtain the desired result, but of course, me-says go to your nearby mechanic and have him replace the programmer (it is a bit costly, but if your LeSabre is in any decent condition it is worth the investment).

SOURCE: 2004 Yukon. driver side air conditioner not working

you need to change drivers side temp door actuator then disconnect battery for 5 seconds and reconnect after changing the part, turn key on for 60 seconds with touching heater control to allow actuator to program and then it will work.