I have read through the manual for the ground air but when it is connected I don't get any air to the aircraft. Packs on engine bleeds on. Recuc fans on. What am I missing.

What you want to know is in the Operating Manual Vol 1. Best way to learn the aircraft is read through all the manuals. Even if you do know how to get it started and take off it wont help if something fails and you do not understand how things work. This is not a takeoff and fly aircraft and if anyone bought it thinking it was they are in for a shock. There is also a flow chart chart checklist on AVSIM specifically for the 737-NGX.

I have read through the manual for the ground air but when it is connected I don't get any air to the aircraft. Packs on engine bleeds on. Recuc fans on. What am I missing.

Ground air? As in air conditioning or starter air? The ground air (A/C) is pushed directly through the manifold. APU/Engine bleeds off. Same for start air. IIRC

I posted about this yesterday as I was unable to start the second engine with the ground air so I looked it up in the FCOM and after starting Engine No. 1 with ground air as you would with the APU then disconnect ground air. You then need to follow the Engine crossbleed start procedure, i.e. Engine bleeds ON, APU bleed... OFF, PACKS... OFF, Isolation valve... AUTO, then (after ensureing nobody's behind the aircraft ;-)) increase thrust of Engine 1 until you get 30 PSI in the bleed duct, then start Engine 2. If you don't increase thrust you won't reach the required N2 of 20% when starting Engine No.2. What a great simulation this is. Hats off to PMDG.