Pinpoint Test 7: The Blower Motor Is Inoperative - Manual Climate Control Module
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PINPOINT TEST 7: THE BLOWER MOTOR IS INOPERATIVE - MANUAL CLIMATE CONTROL MODULE
Normal Operation
The blower motor relay coil receives ignition voltage through circuit (G/BR). The coil receives ground from the electronic manual temperature control (EMTC) module through circuit (V/G) if any function selector position but OFF is selected. Voltage is supplied to the relay switch contact. When the relay coil is energized, voltage is delivered to the blower motor through circuit (Y/G). Ground for the blower motor is provided through circuit (V/O) from the blower resistor or the blower switch (HI). The blower resistor and blower switch is grounded through circuit (B/G).
- DTC B12AF (Front Blower Motor Relay Drive Circuit Shorted to Battery Voltage) - The module senses excessive 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.
Possible Causes
- Fuse(s)
- Wiring, terminals or connectors
- Blower motor
- Blower motor relay
- Blower motor switch
- EMTC module
Diagnostic Procedure
