RAM 2500 Truck 4WD V8-5.7L VIN D (2005)
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(C71) Blower motor low driver circuit/(C73) blower motor M2 driver circuit/(C72) blower motor M1 driver circuit/(C70) blower motor high
driver circuit shorted to voltage
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(C71) Blower motor low driver circuit/(C73) blower motor M2 driver circuit/(C72) blower motor M1 driver circuit/(C70) blower motor high
driver circuit shorted together
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(C71) Blower motor low driver circuit/(C73) blower motor M2 driver circuit/(C72) blower motor M1 driver circuit/(C70) blower motor high
driver circuit open
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Blower motor resistor block open
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A/C heater control
Diagnostic Test
1. CHECK IF THE BLOWER MOTOR RUNS WITH THE BLOWER CONTROL IN THE OFF POSITION
Turn the Blower control to the Off position.
Turn the ignition on.
Q: Does the blower motor run?
YES: Go To 2
NO: Go To 3
2. CHECK THE (C71) BLOWER MOTOR LOW DRIVER CIRCUIT, THE (C73) BLOWER MOTOR M2 DRIVER CIRCUIT, THE
(C72) BLOWER MOTOR M1 DRIVER CIRCUIT, & THE (C70) BLOWER MOTOR HIGH DRIVER CIRCUIT FOR A SHORT TO
GROUND
Turn the ignition off.
Disconnect the A/C Heater Control C2 harness connector.
Disconnect the Blower Motor Resistor Block harness connector.
Measure the resistance of the (C71) Blower Motor Low Driver circuit, the (C73) Blower Motor M2 Driver circuit, the (C72) Blower Motor M1
Driver circuit, and the (C70) Blower Motor High Driver circuit between ground and the A/C Heater Control C2 harness connector.
Q: Is the resistance below 10K ohms on any of the circuits?
YES: Repair all circuits with a resistance below 10K ohms for a short to ground. Perform BODY VERIFICATION TEST - VER 1. See: Testing
and Inspection/Diagnostic Trouble Code Tests and Associated Procedures/Verification Tests/Body Verification Test
NO: Replace the A/C Heater Control. Perform BODY VERIFICATION TEST - VER 1. See: Testing and Inspection/Diagnostic Trouble Code
Tests and Associated Procedures/Verification Tests/Body Verification Test
3. CHECK THE (C71) BLOWER MOTOR LOW DRIVER CIRCUIT, THE (C73) BLOWER MOTOR M2 DRIVER CIRCUIT, THE
(C72) BLOWER MOTOR M1 DRIVER CIRCUIT, & THE (C70) BLOWER MOTOR HIGH DRIVER CIRCUIT USING A TEST
LIGHT