Pinpoint Test J: The Blower Motor Does Not Operate Correctly
Climate Control System
Pinpoint Tests
Pinpoint Test J: The Blower Motor Does Not Operate Correctly
Refer to the Wiring Diagram Climate Control System for schematic and connector information. Diagrams By Number
Normal Operation
Under normal operation, ground for the blower motor is supplied by the blower motor resistor or blower switch. In LOW, the resistor is grounded directly. In MED-LO and MED-HIGH, the resistor is grounded to the blower switch. In HIGH, the blower motor is directly grounded to the blower switch. The blower switch is grounded.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Blower motor resistor
- Blower motor switch
PINPOINT TEST J: THE BLOWER MOTOR DOES NOT OPERATE CORRECTLY
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J1 CHECK THE BLOWER MOTOR OPERATION
- Ignition ON.
- Set the function selector switch in 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 J2.
If the blower motor does not operate in LO setting only, GO to J3.
If the blower motor does not operate in MED-LO or MED-HI setting only, GO to J4.
If the blower motor operates in HI setting only, GO to J6.
If the blower motor operates in LO setting only, GO to J7.
For all other symptoms, GO to J8.
No
GO to Pinpoint Test I. Pinpoint Test I: The Blower Motor is Inoperative
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J2 CHECK CIRCUIT CH430 (VT/OG) FOR AN OPEN
- Ignition OFF.
- Disconnect: Blower Motor Switch C294c.
- Disconnect: Blower Motor C1031.
- Measure the resistance between blower motor switch C294c-2, circuit CH430 (VT/OG), harness side and blower motor C1031-2, circuit CH430 (VT/OG), harness side.
- Is the resistance less than 5 ohms?
Yes
INSTALL a new blower motor switch. TEST the system for normal operation.
No
REPAIR circuit CH430 (VT/OG) for an open. TEST the system for normal operation.
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J3 CHECK BLOWER MOTOR RESISTOR GROUND CIRCUIT GD123 (BK/GY) FOR AN OPEN
- Ignition OFF.
- Disconnect: Blower Motor Resistor C1032.
- Measure the resistance between blower motor resistor C1032-3, circuit GD123 (BK/GY), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
INSTALL a new blower motor resistor. TEST the system for normal operation.
No
REPAIR circuit GD123 (BK/GY) for an open. TEST the system for normal operation.
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J4 CHECK CIRCUIT CH428 (GN/WH) OR CH429 (GY/BN) FOR GROUND
NOTICE: The following step uses a test light to simulate normal circuit loads. Use only the test light recommended in the Special Tools table of equivalent. 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 C1032.
- 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 lamp between blower motor resistor C1032-1, circuit CH430 (VT/OG), harness side and blower motor resistor C1032-4, circuit CH428 (GN/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 lamp between blower motor resistor C1032-1, circuit CH430 (VT/OG), harness side and blower motor resistor C1032-2, circuit CH429 (GY/BN), harness side.
- Does the test lamp illuminate?
Yes
INSTALL a new blower motor resister. TEST the system for normal operation.
No
GO to J5.
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J5 CHECK CIRCUIT CH428 (GN/WH) OR CH429 (GY/BN) FOR AN OPEN
- Ignition OFF.
- Disconnect: Blower Motor Switch C294c.
For MED-LO inoperative
- For MED-LO inoperative, measure the resistance between blower motor switch C294c-4, circuit CH428 (GN/WH), harness side and blower motor resistor C1032-4, circuit CH428 (GN/WH), harness side.
For MED-HI inoperative
- For MED-HI inoperative, measure the resistance between blower motor switch C294c-3, circuit CH429 (GY/BN), harness side and blower motor resistor C1032-2, circuit CH429 (GY/BN), harness side.
- Is the resistance less than 5 ohms?
Yes
CARRY OUT the blower motor resistor component test. If the resistor tests OK, INSTALL a new blower motor switch. TEST the system for normal operation. Climate Control System
No
REPAIR circuit CH428 (GN/WH) or CH429 (GY/BN) for an open. TEST the system for normal operation.
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J6 CHECK CIRCUIT CH430 (VT/OG) FOR AN OPEN
- Ignition OFF.
- Disconnect: Blower Motor Resistor C1032.
- Disconnect: Blower Motor C1031.
- Measure the resistance between blower motor resister C1032-1, circuit CH430 (VT/OG), harness side and blower motor C1031-2, circuit CH430 (VT/OG), harness side.
- Is the resistance less than 5 ohms?
Yes
INSTALL a new blower motor resister. TEST the system for normal operation.
No
REPAIR circuit CH430 (VT/OG) for an open. TEST the system for normal operation.
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J7 CHECK CIRCUIT GD121 (BK/YE) FOR AN OPEN
- Ignition OFF.
- Disconnect: Blower Motor Switch C294c.
- Measure the resistance between ground and blower motor switch C294c-1, circuit GD121 (BK/YE), harness side.
- Is the resistance less than 5 ohms?
Yes
INSTALL a new blower motor switch. TEST the system for normal operation.
No
REPAIR circuit GD121 (BK/YE) for an open. TEST the system for normal operation.
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J8 CHECK CIRCUITS CH430 (VT/OG), CH429 (GY/BN) AND CH428 (GN/WH) FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: Blower Motor C288.
- Disconnect: Blower Motor Resistor C2185.
- Disconnect: Blower Motor Switch C2357b.
- Measure the resistance between ground and blower motor switch:
- C294c-2, circuit CH430 (VT/OG), harness side.
- C294c-3, circuit CH429 (GY/BN), harness side.
- C294c-4, circuit CH428 (GN/WH), harness side.
- Are the resistances greater than 10,000 ohms?
Yes
GO to J9.
No
REPAIR the affected circuit for a short to ground. TEST the system for normal operation.
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J9 CHECK CIRCUITS CH430 (VT/OG), CH429 (GY/BN) AND CH428 (GN/WH) FOR A SHORT TOGETHER
- Measure the resistance between blower motor switch:
- C294c-2, circuit CH430 (VT/OG), harness side and C294c-3, circuit CH429 (GY/BN), harness side.
- C294c-2, circuit CH430 (VT/OG), harness side and C294c-4, circuit CH428 (GN/WH), harness side.
- C294c-4, circuit CH428 (GN/WH), harness side and C294c-3, circuit CH429 (GY/BN), harness side.
- Are the resistances greater than 10,000 ohms?
Yes
CARRY OUT the blower motor resistor component test. If the resistor tests OK, INSTALL a new blower motor switch. TEST the system for normal operation. Climate Control System
No
REPAIR the affected circuits. TEST the system for normal operation.
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