Assuming the climate control functions worked before you took the dash apart, double check the following:

- Both cables plugged firmly into the PBU, and the left and right cables are not confused (not sure if they are keyed but just checking)

- Vacuum present at solenoid manifold under dash and all hoses hooked up

- Solenoid manifold plugged in

- Fuse F7 good, that is the source of power for the PBU/mono valve/aspiration blower/aux pump

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech