Thanks for all the tips. It has been a while since I studied the vacuum routing for the HVAC controls. I was pretty sure I could make it work like I wanted by putting a valve system in the lines. I didn't experiment with it to see if it would work. I thought the heater core for the blend door always had hot coolant flowing through it and that was bypassed in Max A/C. If hot coolant is shut off in Max A/C, I may have to rethink what I need to do.
I have a Ford repair manual with wiring and vacuum diagrams for the 2002 Ranger. Hopefully they are correct. I will study everything to see what it takes to make it work like I want it to. Hopefully it can be done with the control switch. That would make things easier than having to switch a valve or valves when I want to use Max A/C.
Now that I am thinking about it more, I think what I decided would work the best was to have the door the for outside air intake close when in normal A/C instead of making it work like I want in Max A/C, but I don't remember if I came up with a way to do it. I will post if I find a way to do what I want, whatever it is.
As I recall with my 89 STX, all I had to do was switch to 'recirculate air' when off-road. The A/C still worked normally but was not pulling in outside air. I think I could use that recirculate feature on any HVAC setting.