When I turn on the A/C it blows from the defrost by the windshield.
It blows cold air.
I opened the dash and checked the vacuum cylinder, it works OK.
I thing the electric solenoid or gadget that switches the vacuum from one line to the next may be bad, BUT I have no idea where to look.
The one on the right is the unemployed one.
Blue tube runs to a manifold with about five tubes.
This problem is on our 1997 Jayco, Ford E Superduty.