Electric air blend motors are used to direct the air through the HVAC system. They are mounted on the driver and passenger side of the HVAC plenum. (you'll need a manual to verify which is what)
One of these motor assembly's was probable changed out and the incorrect P/N was used to control the main internal door that directs the heat/AC.
I have had this happen to a Buick I owned. The motor was bad, the shop ordered the incorrect p/n and installed it. It fit but operated in reverse of what it should have done. They corrected the problem. But on that car there were, IIRC, 6 different units installed on the plenum.
One of these motor assembly's was probable changed out and the incorrect P/N was used to control the main internal door that directs the heat/AC.
I have had this happen to a Buick I owned. The motor was bad, the shop ordered the incorrect p/n and installed it. It fit but operated in reverse of what it should have done. They corrected the problem. But on that car there were, IIRC, 6 different units installed on the plenum.