HVAC knob won't work at certain settings.

[madcut96]

Hey everyone, I've got a question:

 

My friend has an 06 Malibu Classic, my work has a Colorado, and my Mom has an 02 Monte Carlo SS, and they've all got the same problem, that their HVAC knobs will only work on certain settings. Malibu only 4 and 5, the Colorado only 1-3, and the Monte's only 2-5.

 

Does anyone know what's up and how to fix?

 

Thanks.

[3pt1lumina]

Blower motor resistor card went bad. Happened twice to my 01 Malibu and my 00 GA. On the N bodies, they were pass side of the dash, two small bolts (forget what size, maybe 7 mm) and they unplugged. $40 new from a dealership.