I have a 1999 Ford Explorer, 2- wheel drive with a V-6 engine and automatic transmision.
Why does my air condition change from dash vents to windshield vents when going up a steep hill.?
i would ask the car dealer!!! that sounds like a problem...do some research b4 you make your final thingy!!!
Why does my air condition change from dash vents to windshield vents when going up a steep hill.?
Replace the vacuum check valve feeding the a/c system.
The one on the can under the hood.
at heavy throttle opening with a load such as climbing a steep hill the engine has very little manifold vacuem and the loss of vac signal to the controls of your vents allows it to default to defroster mode.. not a big deal to worry about
