I have a 2000 suburban 2500 LT 4×4 with dual AC. I replaced my battery and noticed afterwards my AC was stuck in defrost. Still coolimg but only blowing from the dash and the mode operation not working.
I found online there was either a recalibration or actuator replacement that needed to be done. Every recalibration I found were for automatic HVAC systems and/or had different fuses than my truck.
My HVAC has manual knobs and separate controls systems for front and back. Including front and rear separate 30 amp fuses The back works fine. Is there a recalibration for my specific HVAC system? I want to try it before I attempt to replace the actuator. Again, this occurred after my battery replacement.
According to GM service information there is no recalibration procedure for your year model Suburban with manual controls. So most likely you will need to replace the mode actuator.