ACC heat /cool mode backards?

[nomorehurry]

There may be something about this on the forum somewhere, but I can't find it.

Car is 82 300DT, 210,000+ miles.

Air Conditioning systems runs fine for a while, then goes to high heat and then to max heat. Auxillary fan does not seem to come on while in cooling mode, but will engage while in heating mode.

Monovalve and wie are good, ACC unit is new (rebuilt) temp wheel has been cleaned and ohm resistance changes as dial is turned, all fan vents and speeds seem to work fine except I get continuous flow through defroster vents either in heat or cool mode.

Questios: what controls change from heating mode to cooling mode and vice-versa? Is there something that could be cross wired that would cause the fan to be reversed? (fan turns in correct direction).

Note: previous owner claims to be a mechanic, but I have already re-fixed much of his work. I am not a a mechanic....

Help is appreciated as both I and my local air conditioning expert are lost. Thanks all.