Normally, I leave HVAC in following setting:
Fan: 1
Temp: Coldest
Mode: Vent
Rec: Off
A/C :Off
Maybe I've never noticed before. After performed DEF mod, A/C compressor will engage briefly first engine start of the day. I didn't open hood to verify clutch engagement but I can hear the clutch engages and cool air blowing.
Is this normal for Delphi designed HVAC (with or without DEF mod) or something is going downhill?
A/C not kicked in.