Brian
Kind of confusing what's going on.
Would you say that sometimes it blows hot air (even though you don't want it to, say you have it set at max cool and it blows hot air) and other times you actually want heat but it doesn't blow hot at all?
If you run the AC is the clutch coming on, or don't you know that?
Is the blower fan working OK, or is that screwed up too?
Is the engine getting up to operating temp or is that fluctuating up and down? Should run about 80 C.

Gilly