Rear Blower Motor

The rear Auxiliary Blower Motor controls operate by grounding the Auxiliary Blower Motor Relays through switch contacts. Battery voltage from RR BLOWER Fuse is available at all times to the normally open contacts of each of the three Auxiliary Blower Motor Relays. When one of the relays operates, voltage is applied to the Auxiliary Blower Motor. Since the Auxiliary Blower Motor is grounded at Ground G400 by the BLK (150) wire, the motor operates.

Battery voltage is available from RR HVAC Fuse 12 through the BRN (341) wire to the coils of each of the three Auxiliary Blower Motor Relays. This voltage is available when the Ignition Switch is in the Run position and is used to operate the relays. The Auxiliary Blower Motor Switch grounds the coil of the selected relay through the BLK (150) wire to Ground G400. When the relay coil is grounded through the Auxiliary Blower Motor Switch, current flows through the relay coil. This energizes the relay to close the relay's normally-open contacts. Voltage is supplied to the relay contacts at all times by the RED (1542) wire from the HVAC Maxi Fuse. When the relay contacts close. this voltage is applied to operate the motion

Placing the Auxiliary Blower Motor Switch in the LOW position grounds the coil of the Auxiliary Blower Motor Low Speed Relay through the DK BLU (1926)1 YEL (60) wire. The relay's contacts close and apply operating voltage on the YEL (1176) wire. Current flow is through both the resistors in the Auxiliary Blower Motor Resistor and then through the YEL (1172) wire to the Auxiliary Blower Motor. The voltage drop through the two resistors limits the Auxiliary Blower Motor to its lowest speed.

Placing the Auxiliary Blower Motor Switch in the Medium position grounds the coil of the Auxiliary Blower Motor Medium Speed Relay through the RED (1925) I TAN (63) wire. The relay's contacts close and apply operating voltage on the LT BLU (1072) wire. Current flow is through only one of the resistors in the Auxiliary Blower Motor Resistor and then through the YEL (1172) wire to the Auxiliary Blower Motor. The voltage drop through the single resistor allows the Auxiliary Blower Motor to operate at a higher speed.

Placing the Auxiliary Blower Motor Switch in the HIGH position grounds the coil of the Auxiliary Blower Motor High Speed Relay through the WHT (1924)1 ORN (52) wire. The relay's contacts close and apply operating voltage directly on the YEL (1172) wire. Current flow bypasses the resistors in the Auxiliary Blower Motor Resistor. This full battery voltage allows the Auxiliary Blower Motor to operate at its highest speed.