GMC YUKON VENT

It Will Not Switch To Defrost Vent, Floor Vents. Where Is The Expansion Valve And Lines Located Under Hood So I Can Check For Leaks? Or...

When I Pluged In The New Motor It Rotated Clockwise And Stopped. It Will Rotate Back No Matter What The Vent Selestor Is Set To.

My Vents Will Not Closed Even When Switch Is Closed. Can't Blend Temperatures. Either Hot Or Cold, Not Warm. Controls Will Not Change...

When Front Dash Vents Are On There Is Little Air Coming Out. We Can Feel Some, But Not Much. Rear Roof Vent System Works Great.