Test P

PINPOINT TEST P: THE AUXILIARY BLOWER MOTOR DOES NOT OPERATE CORRECTLY

Test P1-P3:

Test P3-P6:

Test P6-P7:

Test P8-P9:

Test P10-P13:

Test P13-P14:

Normal Operation
Under normal operation, 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). The blower motor speed relay coils are supplied through circuit 1460 (RD/YE). Blower motor speed is received by the SJB from the rear auxiliary control through circuit 1349 (PK/LG). Reference voltage for the blower speed selector resistor is provided by the SJB through circuit 536 (BK/LG). The auxiliary blower motor relay coil receives ground from the Smart Junction Box (SJB) through circuit 1371 (TN/OG) if any blower switch position but OFF is selected.

In LO, ground for the blower motor is provided through the blower motor resistor.

In MED-LO, blower motor speed relay 2 is grounded by the SJB through circuit 1373 (GY/YE). Blower motor ground circuit 515 (OG/RD) is connected through one half of the blower motor resistor to circuit 751 (DB/WH). Circuit 751 (DB/WH) is connected through blower motor speed relay 2 to the blower motor resistor ground circuit 1205 (BK) by circuit 752 (YE/RD).

In MED-HI, blower motor speed relay 1 is grounded by the SJB through circuit 1372 (PK/BK). Blower motor ground circuit 515 (OG/RD) is connected through blower motor speed relay 2 to circuit 751 (DB/WH). Circuit 751 (DB/WH) is connected through one half of the blower motor resistor to the blower motor resistor ground circuit 1205 (BK).

In HI, blower motor speed relays 1 and 2 are grounded by the SJB through circuit 1372 (PK/BK) and 1373 (GY/YE). Blower motor ground circuit 515 (OG/RD) is connected through blower motor speed relay 1 to circuit 751 (DB/WH). Circuit 751 (DB/WH) is connected through blower motor speed relay 2 to the blower motor resistor ground circuit 1205 (BK) by circuit 752 (YE/RD).

Possible Causes
- An open in circuit 1372 (PK/BK), 1373 (GY/YE), 1349 (PK/LG), 1460 (RD/YE), 751 (DB/WH), 752 (YE/RD) or 515 (OG/RD).
- A short to ground in circuit 1371 (TN/OG), 1372 (PK/BK), 1373 (GY/YE), 1349 (PK/LG) or 751 (DB/WH).
- A short to voltage in circuit 1348 (GY/OG), 1372 (PK/BK), 1373 (GY/YE), 1349 (PK/LG) or 536 (BK/LG).
- A short together circuits 751 (DB/WH) and 515 (OG/RD)
- Blower motor relay.
- Blower motor speed relay 1.
- Blower motor speed relay 2.
- Rear auxiliary control.
- Auxiliary blower motor resistor.
- SJB.