Heater/AC problem. Hot air barely warm & cold air barely cool. Fan is OK I think. on 2002 Volkswagen Passat

I've had a problem with the heater and air conditioner for the last two seasons. Both systems are weak, meaning that the heater barely puts out warm air and the AC system barely puts out cool air. The fan seems to work fine. I was told the problem is the motor, but I'm not confident about that. Does anyone have information about this problem?

Asked by for the 2002 Volkswagen Passat
the only basic test you can do is to cycle the blower thru
all its speeds to make sure it works correctly. after that,
you will need a good local shop that is a VW specialist. you may have more than just one issue.