Temperature Control Dial
WARNING: This page is about a different car, the 1998 Subaru Impreza. However, it is still accessible from the selected car via links, so may be relevant.
Temperature control dial controls air temperature and can be set at any position between COLD and HOT. With temperature control dial in COLD position, air is directed around heater core. With temperature control dial in HOT position, air is directed through heater core. With temperature control dial positioned at various intervals between HOT and COLD, intermediate blend-air temperatures are obtained.