Normal Operation
WARNING: This page is about a different car, the 2003 Lincoln Aviator. However, it is still accessible from the selected car via links, so may be relevant.
Under normal operation, the Automatic Temperature Control (ATC) solenoid and manifold receives a ground from the Dual Automatic Temperature Control (DATC) module through circuit 1070 (BN/LB). When the heater control valve vacuum solenoid is to be energized, the ATC solenoid and manifold receives power from the DATC module through circuit 1069 (OG/LB).