Volvo Repair: Climate control- Blower Control, proper diagnosis, blower system

Question
Greetings Regis,
We have a 1997 850 GLT Sportswagon which recently developed a malfunction in the Climate control blower system.  The blower functions while in the off setting, heat comes out of the duct when set on A/C and visa-versa. Ironically, we get heat in the summer and cold in the winter. It seems as though a door within the ductwork is either stuck or being improperly controlled. Is there a relay or brain controlling this system, or notorious loose connection to check.  Also, a mildew smell appears to be emimating from the evaporator.  Your input is appreciated.

Answer
all this would be controlled from the ac control panel which is also like the control unit for the air conditioner system.it is possible the control panel is bad.the only way to be sure is to have it looked at for a proper diagnosis.diagnostic trouble codes can be pulled from the control panel with a special tool and this may give some indication as to the problem.

the smell may be from freon leaking from the evaporator which they often do.or the addititon of an after blower kit which dries the evaporator off after the vehicle is shut off may help eliminate this.