Ford Expedition Air Conditioner Expansion Valve

I Have A Ford Expedition 2007, The Rear A/c All Of A Sudden Blow Warm Air, The Front A/c Is Good, The Freon Is Fully Charged, Both Line...

Is The Expansion Valve For The Interior Climate Control In Any Way Connected To The Vac Hub Of The Wheel Bearing?

I Want To Charge The Airconditioner. Where Is The Valve And What Should I Be Careful Of?

Auto Has 2 Ac Units. Both Units Will Blow Cold Air For A Short Time And Then Quit Cooling. I Have Taken It To The Ford Dealership And They...