Don't take this the wrong way!!!
 

Ok now that I have your attention! I got my Ranger in January and it has ran fine. The only problem with it is when ever the heat or a/c or air is on, and i go up hills (on the highway or secondary roads,) it stops blowing air at all. This is becoming a problem when I am going up any long hill and I noticed it doing it on any slight incline. Anybody have a clue as to what is wrong? Oh and the engine runs fine while this is happening.

If you floor it, the compressor will cut off so your engine gets maximum power during acceleration!

Correct. It is NOT normal for the blower to cut off. Only the AC compressor. Are you sure it's not blowing air?

Check to see if the air discharge on the hills is changing to the defrost outlets rather than stopping completely. If so, then you are losing vacuum to the door servos when the engine vacuum is low. This means a vacuum leak or bad check valve in the AC reservoir. A fairly common leak in 98~2000 1/2 4x4's could be the PVH vacuum.

Please don't use misleading or ambiguous titles for your threads.

Wow, good call. I completely forgot about that problem, Bob.

My bet is on Vaccum loss too. I think one other person here had this problem and that was the culprit.

So best bet is to take it to the dealer to figure it out. And sry bout the title, still a newbie!!