Test O: The Auxiliary Blower Motor Is Inoperative

PINPOINT TEST O: THE AUXILIARY BLOWER MOTOR IS INOPERATIVE

O1:

O2-O4:

O5-O7:

O7-O8:

Normal Operation
Under normal operation, the auxiliary blower motor relay coil receives ignition voltage through circuit 181 (BN/OG). The coil receives ground from the electronic automatic temperature control (EATC) module through circuit 1371 (TN/OG) if any auxiliary blower speed but OFF is selected. Voltage is supplied to the relay switch contact through circuit 1004 (LB/RD). 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 1349 (PK/LG) from the blower motor resistor. The blower resistor is grounded through circuit 1205 (BK).

Possible Causes
- An open in circuit 181 (BN/OG), 1004 (LB/RD), 1371 (TN/OG), 1205 (BK), 536 (BK/LG) or 1349 (PK/LG).
- Auxiliary blower motor
- Auxiliary blower motor relay 1
- Auxiliary blower motor resistor