Pinpoint Test P: The Blower Motor Does Not Operate Correctly - Manual Climate Control
Climate Control System
Pinpoint Tests
Pinpoint Test P: The Blower Motor Does Not Operate Correctly - Manual Climate Control
Refer to Wiring Diagram Set 54, Manual Climate Control System for schematic and connector information. Diagrams By Number
Normal Operation
Under normal operation, the blower motor is provided a ground through the entire blower resistor in the lowest blower setting. In MED-LO and MED-HI, the resistor gets a ground from the blower motor switch. In HI, the blower motor is grounded directly through the blower motor switch. The blower switch is provided a ground.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Blower motor switch
- Blower motor resistor
PINPOINT TEST P: THE BLOWER MOTOR DOES NOT OPERATE CORRECTLY - MANUAL CLIMATE CONTROL
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P1 CHECK THE BLOWER MOTOR OPERATION
- Ignition ON.
- Turn the function selector switch to the FLOOR position.
- Select all blower speed positions.
- Does the blower motor operate in any position?
Yes
If the blower motor does not operate in HI setting only, GO to P2.
If the blower motor does not operate in LO setting only, GO to P3.
If the blower motor does not operate in MED-LO or MED-HI setting only, GO to P4.
If the blower motor operates in HI setting only, GO to P6.
If the blower motor operates in LO setting only, GO to P7.
For all other symptoms, GO to P8.
No
GO to Pinpoint Test O. Pinpoint Test O: The Blower Motor Is Inoperative - Manual Climate Control
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P2 CHECK THE BLOWER MOTOR RESISTOR CIRCUIT 261 (OG/BK) FOR AN OPEN
- Ignition OFF.
- Disconnect: Blower Motor Switch C294B.
- Disconnect: Blower Motor C1227.
- Measure the resistance between blower motor switch C294B-3, circuit 261 (OG/BK), harness side and blower motor C1227-2, circuit 261 (OG/BK), harness side.
- Are the resistances less than 5 ohms?
Yes
INSTALL a new blower motor switch. TEST the system for normal operation.
No
REPAIR circuit 261 (OG/BK) for an open. TEST the system for normal operation.
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P3 CHECK BLOWER MOTOR RESISTOR GROUND CIRCUIT 57 (BK) FOR AN OPEN
- Ignition OFF.
- Disconnect: Blower Motor Resistor C1349.
- Measure the resistance between blower motor resistor C1349-2, circuit 57 (BK), harness side and ground.
- Are the resistance less than 5 ohms?
Yes
INSTALL a new blower motor resistor. TEST the system for normal operation.
No
REPAIR circuit 57 (BK) for an open. TEST the system for normal operation.
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P4 CHECK THE BLOWER MOTOR SWITCH
NOTICE: The following step uses a test light to simulate normal circuit loads. Use only the test light recommended in the Special Tools table. To avoid connector terminal damage, use the Flex Probe Kit for the test light probe connection to the vehicle. Do not use the test light probe directly on any connector.
- Ignition OFF.
- Disconnect: Blower Motor Resistor C1349.
- Ignition ON.
For MED-LO inoperative
- For MED-LO inoperative: With the blower motor switch in the MED-LO speed position, connect a 12-volt test light between blower motor resistor C1349-4, circuit 261 (OG/BK), harness side and blower motor resistor C1349-1, circuit 754 (LG/WH), harness side.
For MED-HI inoperative
- For MED-HI inoperative: With the blower motor switch in the MED-HI speed position, connect a 12-volt test light between blower motor resistor C1349-4, circuit 261 (OG/BK), harness side and blower motor resistor C1349-3, circuit 754 (YE/RD), harness side.
- Does the test light illuminate?
Yes
INSTALL a new blower motor resistor. TEST the system for normal operation.
No
GO to P5.
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P5 CHECK CIRCUITS 752 (YE/RD) AND 754 (LG/WH) FOR AN OPEN
- Ignition OFF.
- Disconnect: Blower Motor Switch C294B.
- Disconnect: Blower Motor Resistor C1349.
For MED-LO inoperative
- For MED-LO inoperative: Measure the resistance between blower motor switch C294B-1, circuit 754 (LG/WH), harness side and blower motor resistor C1349-1, circuit 754 (LG/WH), harness side.
For MED-HI inoperative
- For MED-HI inoperative: Measure the resistance between blower motor switch C294B-4, circuit 752 (YE/RD), harness side and blower motor resistor C1349-3, circuit 752 (YE/RD), harness side.
- Are the resistances less than 5 ohms?
Yes
CARRY OUT the Blower Motor Resistor component test Climate Control System. If the resistor tests OK, INSTALL a new blower motor switch. TEST the system for normal operation.
No
REPAIR the affected circuit for an open. TEST the system for normal operation.
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P6 CHECK THE BLOWER MOTOR RESISTOR CIRCUIT 261 (OG/BK) FOR AN OPEN
- Ignition OFF.
- Disconnect: Blower Motor Resistor C1349.
- Disconnect: Blower Motor C1227.
- Measure the resistance between blower motor resistor C1349-4, circuit 261 (OG/BK), harness side and blower motor C1227-2, circuit 261 (OG/BK).
- Are the resistances less than 5 ohms?
Yes
INSTALL a new blower motor resistor. TEST the system for normal operation.
No
REPAIR circuit 261 (OG/BK) for an open. TEST the system for normal operation.
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P7 CHECK CIRCUIT 57 (BK) FOR AN OPEN
- Measure the resistance between blower motor switch C294B-2, circuit 57 (BK), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
INSTALL a new blower motor switch. TEST the system for normal operation.
No
REPAIR circuit 57 (BK) for an open. TEST the system for normal operation.
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P8 CHECK CIRCUITS 261 (OG/BK), 752 (YE/RD) AND 754 (LG/WH) FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: Blower Motor C1227.
- Disconnect: Blower Motor Switch C294B.
- Disconnect: Blower Motor Resistor C1349.
- Measure the resistance between ground and blower motor resistor:
- C1349-4, circuit 261 (OG/BK), harness side.
- C1349-3, circuit 752 (YE/RD), harness side.
- C1349-1, circuit 754 (LG/WH), harness side.
- Are the resistances greater than 10,000 ohms?
Yes
GO to P9.
No
REPAIR the affected circuit for a short to ground. TEST the system for normal operation.
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P9 CHECK THE BLOWER MOTOR CIRCUITS FOR SHORTS TOGETHER
- Measure the resistance between blower motor resistor:
- C1349-4, circuit 261 (OG/BK), harness side and C1349-3, circuit 752 (YE/RD), harness side.
- C1349-4, circuit 261 (OG/BK), harness side and C1349-1, circuit 754 (LG/WH), harness side.
- C1349-3, circuit 752 (YE/RD), harness side and C1349-1, circuit 754 (LG/WH), harness side.
- Are the resistances greater than 10,000 ohms?
Yes
INSTALL a new blower motor switch. REFER to Climate Control Blower Motor Switch. TEST the system for normal operation.
No
REPAIR the affected circuits. TEST the system for normal operation.
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