Normal Operation
WARNING: This page is about a different car, the 2004 Mercury Monterey and 2004 Ford Freestar. However, it is still accessible from the selected car via links, so may be relevant.
Under normal operation, the auxiliary blower motor relay coil receives ignition voltage through circuit 181 (BN/OG). The coil receives ground from the Smart Junction Box (SJB) through circuit 1371 (TN/OG) if any blower switch position but OFF is selected. Voltage is supplied to the relay switch contact through circuit 181 (BN/OG). When the relay coil is energized, voltage is delivered to the blower motor through circuit 536 (BK/LG). Ground for the blower motor is provided through circuit 515 (OG/RD) from the blower motor resistor (LO and MED-LO) and the blower motor speed relay 1 (MED-HI and HI). The blower resistor is grounded through circuit 1205 (BK).