Test I: The Auxiliary Blower Motor Is Inoperative

PINPOINT TEST I: THE AUXILIARY BLOWER MOTOR IS INOPERATIVE

I1:

I2-I4:

I5-I7:

Normal Operation
Under normal operation, the auxiliary blower motor relay 1 coil receives a ground through circuit 57 (BK). The relay 1 coil receives voltage from circuit 753 (YE/RD) if any position but OFF is selected. Voltage is supplied to the relay 1 switch from circuit 884 (YE/BK). When the relay 1 coil is energized, voltage is delivered to the blower motor through circuit 371 (PK/WH). Ground for the motor is provided through circuit 261 (OG/BK) from auxiliary blower motor relay 2. In any speed except HI, ground is provided to relay 2 switch through the auxiliary resistor. Ground for the auxiliary resistor is provided by circuit 57 (BK). In HI, ground is provided to relay 2 switch through 57 (BK).

The auxiliary blower motor relay 2 coil receives voltage from circuit 753 (YE/RD) if any position but OFF is selected. When the auxiliary blower motor switch is in the HI position, ground is provided to the relay 2 coil through circuit 757 (RD/WH). When relay 2 is energized, the auxiliary blower motor is grounded directly through circuit 57 (BK).

Possible Causes
- Fuse(s)
- An open in circuit 57 (BK), 261 (OG/BK), 371 (PK/WH), 753 (YE/RD), 757 (RD/WH) or 884 (YE/BK)
- Auxiliary blower motor relay 1
- Auxiliary blower motor relay 2
- Auxiliary blower motor switch
- Auxiliary blower motor resistor
- Auxiliary blower motor
- Function selector switch