Why do you think that replacing the alternator would fix the heat or AC??
The alternator would/has fixed the battery light being on, but it has no connection to your other problems.

What are the symptons of the heat and AC problems??
Fan not running?? or only running on high speed??
No change in heat output regardless of lever position??

Tell us what is happening (or not happening) and we will have a go at giving some advice.

Regards

PK