why does ac stop blowing when you are in passing gear or van gears down on incline ?

The HVAC system uses vacuum to control the mode selection .. There is a vacuum leak under the hood that's causing the air to switch from dash vents to the defrost vents during 'low' engine vacuum conditions such as acceleration of climbing hills .. It not going to hurt anything but the A/C will certainly perform better if it's fixed!

thanks for info. if u ever have ques. on residential ac hit me up, thats what i do

✔