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Climate Control Pinpoint Test 7: Blower Motor Does Not Operate

CLIMATE CONTROL PINPOINT TEST 7 CHART - BLOWER MOTOR DOES NOT OPERATE

PINPOINT TEST 7 BLOWER MOTOR DOES NOT OPERATE
STEP INSPECTION ACTION
1 CHECK THE BLOWER MOTOR
  • Key OFF.
  • Disconnect blower motor connector 0740-106.
  • Connect battery voltage and ground to the blower motor.
  • Does the blower motor operate? 
 Yes Go to step 2.
No Install a new blower motor. Test the system for normal operation.
2 CHECK FOR VOLTAGE TO THE BLOWER MOTOR
  • Key ON engine off (KOEO).
  • Set the function selector switch in the FLOOR position.
  • Measure the voltage between the blower motor 0740-106 pin 2, (P/W) and ground.
  • Is the voltage greater than 10 volts? 
 Yes Go to step 3.
No Go to step 4.
3 CHECK CIRCUIT (O/B) FOR AN OPEN
  • Key ON engine off.
  • Connect the blower motor connector 0740-106.
  • Key ON engine off (KOEO).
  • Set the function selector switch to HI fan and FLOOR position.
  • Does the fan operate? 
 Yes Go to CLIMATE CONTROL PINPOINT TEST 10: NO OPERATION IN LOWER SPEEDS 
No Repair circuit (O/B) or (B) for an open between heater blower motor and ground (through heater blower motor resistor). Test the system for normal operation.
4 CHECK CIRCUIT (P/W) FOR AN OPEN
  • Key off.
  • Disconnect blower motor relay and blower motor connector 0740-106.
  • Measure the resistance between the blower motor 0740-106, pin 2, (P/W) and the relay blower motor relay socket pin 30 (P/W).
  • Is the resistance less than 5 ohms? 
 Yes Go to step 5.
No Repair circuit (P/W) for an open. Test the system for normal operation.
5 CHECK CIRCUIT (R/O) FOR VOLTAGE
  • Key ON, engine off (KOEO).
  • Measure the voltage between the blower motor relay socket, (R/O) and ground.
  • Is the voltage greater than 10 volts? 
 Yes Go to step 6.
No Repair circuit (R/O) for open. Test the system for normal operation.
6 CHECK CIRCUIT (B) FOR OPEN
  • Key OFF.
  • Measure the resistance between the blower motor relay socket pin 85, (B) and ground.
  • Is the resistance less than 5 ohms? 
 Yes Go to step 7.
No Repair circuit (B) for an open. Test the system for normal operation.
7 CHECK FOR VOLTAGE TO THE BLOWER MOTOR RELAY, COIL SIDE
  • Key ON, engine off (KOEO).
  • Measure the voltage between the blower motor relay socket pin 86, (R/O) and ground.
  • Is the voltage greater than 10 volts? 
 Yes Install a new blower motor relay. Test the system for normal operation.
No Go to step 8.
8 CHECK CIRCUIT (B/LG) FOR OPEN
  • Key OFF.
  • Disconnect the function selector switch connector 0740-101.
  • Key ON, engine off (KOEO).
  • Measure the voltage between the function selector switch 0740-101 pin 3, (B/LG) and ground.
  • Is the voltage greater than 10 volts? 
 Yes Go to step 9.
No Repair circuit B/LG for an open. Test the system for normal operation.
9 CHECK CIRCUIT (R/O) FOR OPEN
  • Key OFF.
  • Measure the resistance between the function selector switch 0740-101 pin 4, (R/O) and the blower motor relay socket pin 86, (R/O).
  • Is the resistance less than 5 ohms? 
 Yes Install a new function selector switch. Test the system for normal operation.
No Repair circuit (R/O) for an open. Test the system for normal operation.
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