Thanks for the solution!!!
Thank you, Knucklebuster! It took me about 12 tries, but your simple solution of On/Off without cranking worked like a charm! :great:
First attempt - Nothing
Second attempt - When I turned the key to ON, the actuators switched and cold air started blowing through the vents. Temporary fix, because as soon as I turned the ignition to start the truck, the air diverted right back to defroster.
Third attempt - Air momentarily switched to dash, but even before I could crank the truck (2003 Suburban 1500), the air diverted right back to the defroster.
Fourth and final try - Air was blowing through the defroster when I turned the key to ON; I left the key ON, and waited a few seconds (maybe 5?) and the air switched over to the dashboard vents. I let it stay that way for a few more seconds, and nothing changed, so I held my breath and turned the ignition. Truck fired up, A/C is blowing ice cold through the dashboard again, and all is good in this 100° Texas heat!
Problem started when AutoZone disconnected the battery, and I was told later by a mechanic about the computer/actuator thing. I didn't want to take it to the local GM dealer and shell out ANOTHER arm and leg, so I thought I'd try the internet first.
Thanks to all for sharing the problem as well as the solution!
Originally Posted by F E Knucklebuster