Test H: The Blower Motor Is Inoperative
PINPOINT TEST H: THE BLOWER MOTOR IS INOPERATIVENormal Operation
Under normal operation, the blower motor relay coil receives ignition voltage through circuit CDC33 (VT/GN). The coil receives ground from the HVAC module through circuit CH123 (VT/GN) if any function selector position but OFF is selected. Voltage is supplied to the relay switch contact through circuit SBB12 (GN/RD). When the relay coil is energized, voltage is delivered to the blower motor through circuit CH402 (YE/GN). Ground for the blower motor is provided through circuit VH301 (YE/BU) from the blower resistor or the blower switch (HI). The blower resistor and blower switch is grounded through circuit GD138 (BK/WH).
- DTC B12AF Front Blower Motor Relay Drive Circuit Shorted to Battery Voltage - The module senses voltage on the relay coil ground circuit, indicating a short directly to voltage.
- DTC B12B0 Front Blower Motor Relay Drive Circuit Open or Shorted to Ground - The module senses no voltage on the relay coil ground circuit, indicating an open or a short directly to ground.
This pinpoint test is intended to diagnose the following:
- Fuse(s)
- Wiring, terminals or connectors
- Blower motor
- Blower motor relay
- Blower motor switch
- HVAC module
H1-H2:
H2-H4:
H4-H6:
H7-H8:
