I just fixed the same problem on my 96 park ave. You probably have a broken air mix actuator. There are 2 on the car but the one on the passenger side seems to fail most often. Open the glove box all the way down. You need to fold in the rubber stoppers attached to the back side of the glove box to release it all the way down. Once you do that you will see a silver metal arm that connects the actuator to the vent door on that side of the car. If you can move it back and forth, you have a broken gear inside the actuator. Local parts stores by me don't carry it so I bought mine through GM Parts Direct for $50 plus shipping.
your blend door which cost about $1000-1500
Smoke could be coming from the vents of your car for a number of reasons. You may have an internal car fire.
The Avalanche has dual controls for the air conditioning system. One control operates the driver side ac vents, and the other control operates the passenger side vents.
My ac blows only in the defroster and not any of the other vents i have 98 ford windstar 3.8 v6
The air is off.
heater core needs replacement
It is called condensation.
If antifreeze is filtering through your ac vents, other toxins could also be coming through. Don't take chances; see a mechanic.
AC VENTS are in the correct position if they are open and free flowing. Some systems have a heat and an AC position for the vents. The AC position is so the cool air discharges from the vents higher on the walls or from the dash rather than floor or windshield in a car.
replace the temperature switch it i sthe one on the right of three in the middle of dash I have same problem on my 98 it took me like 6 hours to get to the problem but it worth
replace? why not fix it?
prior out with a flat screw driver