Something is wrong with the hvac unit in my 2002 mc ls, I switch from off to 5 and nothing changes. The rear defrost will not work and neither will the circulation buttons. 2 months ago I replaced my BCM and ignition switch, no problems since, if that makes a difference. The heat system will occasionally work but it surprises me if it does.
Also, my cruise control light will flicker and will not work when the hvac does not work. I know it could be a few options but I'm not sure. Any help would be greatly appreciated!