Temperature Lever
WARNING: This page does not describe the selected car, but rather 13 other vehicles, including the 1984 Mercury Topaz, 1984 Mercury Marquis, 1984 Mercury Lynx, 1984 Mercury Grand Marquis, and 1984 Mercury Cougar. However, it is still accessible from the selected car via links, so may be relevant.
Temperature lever is connected by a cable to blend air door. When lever is in "COOL" position, air by-passes heater core. In WARM" position, air is directed through heater core. In intermediate positions, air is directed both through and around heater core and mixed to produce air of the desired temperature.