Malibu 2001-2005

Alternator

Print

Diagnosis & Testing



Alternator Load Test
  1. With the engine running, turn on the blower motor and the high beams ( or other electrical accessories to place a load on the charging system).
  2.  
  3. Increase and hold engine speed to 2000 rpm.
  4.  
  5. Measure the voltage reading at the battery.
  6.  
  7. The voltage should increase at least 0.5 volts from the voltage test. If the voltage does not meet specifications, the charging system is malfunctioning.
    NOTE
    Usually under and overcharging is caused by a defective alternator, or its related parts (regulator), and replacement will fix the problem; however, faulty wiring and other problems can cause the charging system to malfunction. Many automotive parts stores have alternator bench testers available for use by customers. An alternator bench test is the most definitive way to determine the condition of your alternator.

  8.  

Alternator No-Load Test
  1. Connect a tachometer to the engine.
    CAUTION
    Ensure that the transmission is in Park and the emergency brake is set. Blocking a wheel is optional and an added safety measure.

  2.  
  3. Turn off all electrical loads (radio, blower motor, wipers, etc.)
  4.  
  5. Start the engine and increase engine speed to approximately 1500 rpm.
  6.  
  7. Measure the voltage reading at the battery with the engine holding a steady 1500 rpm. Voltage should have raised at least 0.5 volts, but no more than 2.5 volts.
  8.  
  9. If the voltage does not go up more than 0.5 volts, the alternator is not charging. If the voltage goes up more than 2.5 volts, the alternator is overcharging.
    NOTE
    Usually under and overcharging is caused by a defective alternator, or its related parts (regulator), and replacement will fix the problem; however, faulty wiring and other problems can cause the charging system to malfunction. Many automotive parts stores have alternator bench testers available for use by customers. An alternator bench test is the most definitive way to determine the condition of your alternator.

  10.  
  11. If the voltage is within specifications, proceed to the next test.
  12.  

Load Test
  1. With the engine running, turn on the blower motor and the high beams ( or other electrical accessories to place a load on the charging system).
  2.  
  3. Increase and hold engine speed to 2000 rpm.
  4.  
  5. Measure the voltage reading at the battery.
  6.  
  7. The voltage should increase at least 0.5 volts from the voltage test. If the voltage does not meet specifications, the charging system is malfunctioning.
    NOTE
    Usually under and overcharging is caused by a defective alternator, or its related parts (regulator), and replacement will fix the problem; however, faulty wiring and other problems can cause the charging system to malfunction. Further testing, which is not covered by this book, will reveal the exact component failure. Many automotive parts stores have alternator bench testers available for use by customers. An alternator bench test is the most definitive way to determine the condition of your alternator.

  8.  

No Load Test
  1. Connect a tachometer to the engine.
    CAUTION
    Ensure that the transmission is in Park and the emergency brake is set. Blocking a wheel is optional and an added safety measure.

  2.  
  3. Turn off all electrical loads (radio, blower motor, wipers, etc.)
  4.  
  5. Start the engine and increase engine speed to approximately 1500 rpm.
  6.  
  7. Measure the voltage reading at the battery with the engine holding a steady 1500 rpm. Voltage should have raised at least 0.5 volts, but no more than 2.5 volts.
  8.  
  9. If the voltage does not go up more than 0.5 volts, the alternator is not charging. If the voltage goes up more than 2.5 volts, the alternator is overcharging.
    NOTE
    Usually under and overcharging is caused by a defective alternator, or its related parts (regulator), and replacement will fix the problem; however, faulty wiring and other problems can cause the charging system to malfunction. Further testing, which is not covered by this book, will reveal the exact component failure. Many automotive parts stores have alternator bench testers available for use by customers. An alternator bench test is the most definitive way to determine the condition of your alternator.

  10.  
  11. If the voltage is within specifications, proceed to the next test.
  12.  

Voltage Test
  1. Make sure the engine is OFF , and turn the headlights on for 15-20 seconds to remove any surface charge from the battery.
  2.  
  3. Using a DVOM set to volts DC, probe across the battery terminals.
  4.  
  5. Measure the battery voltage.
  6.  
  7. Write down the voltage reading and proceed to the next test.
  8.  

Removal & Installation



2.2L Engine
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    Air intake assembly
     
    Oil dipstick assembly mounting bolt
     
    Accessory drive belt
     
    Alternator electrical connectors
     
    Alternator
     

  4.  

To install:

  1. Install or connect the following:

    Alternator. Tighten bolts to 16 ft. lbs. (22 Nm)
     
    Alternator electrical connections. Tighten nut to 15 ft. lbs. (20 Nm).
     
    Accessory drive belt
     
    Oil dipstick assembly mounting bolt
     
    Air intake assembly
     
    Negative battery cable
     

  2.  

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    Air intake assembly
     
    Oil dipstick assembly mounting bolt
     
    Accessory drive belt
     
    Alternator electrical connectors
     
    Alternator
     

  4.  

To install:

  1. Install or connect the following:

    Alternator. Tighten bolts to 16 ft. lbs. (22 Nm)
     
    Alternator electrical connections. Tighten nut to 15 ft. lbs. (20 Nm).
     
    Accessory drive belt
     
    Oil dipstick assembly mounting bolt
     
    Air intake assembly
     
    Negative battery cable
     

  2.  

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Disconnect negative battery cable.
  4.  
  5. Remove the air cleaner resonator.
  6.  
  7. Remove the drive belt.
  8.  
  9. Remove the radiator inlet hose.
  10.  
  11. Disconnect the engine wiring harness electrical connector from the alternator.
  12.  
  13. Reposition the engine wiring harness lead rubber boot.
  14.  
  15. Remove the engine wiring harness terminal lead to alternator nut.
  16.  
  17. Remove the engine wiring harness terminal from the alternator stud.
  18.  
  19. Remove the alternator r bolts.
  20.  
  21. Remove the alternator.

    Click image to see an enlarged view

    Fig. 2.2L Engine alternator and mounting bolts

  22.  

To install:

  1. Position the alternator to the engine block.
  2.  
  3. Install the alternator bolts and tighten to 16 ft. lbs. (22 Nm).
  4.  
  5. Install the engine wing harness terminal to the alternator stud.
  6.  
  7. Install the engine wiring harness terminal lead to alternator nut and tighten to 15 ft. lbs.(20 Nm).
  8.  
  9. Position the engine wiring harness lead rubber boot.
  10.  
  11. Connect the engine wiring harness electrical connector to the alternator.
  12.  
  13. Install the radiator inlet hose.
  14.  
  15. Install the drive belt.
  16.  
  17. Install the air cleaner resonator.
  18.  
  19. Connect negative battery cable.
  20.  
  21. Fill and bleed the cooling system.
  22.  

3.1L & 3.5L Engines
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    Accessory drive belt
     
    Alternator electrical connectors
     
    Power steering line clip
     
    Alternator
     

  4.  

To install:

  1. Install or connect the following:

    Alternator. Torque the nuts to 22 ft. lbs. (30 Nm) and the bolts to 37 ft. lbs. (50 Nm).
     
    Alternator electrical connector
     
    Power steering line clip
     
    Accessory drive belt
     
    Negative battery cable
     

  2.  

3.5L Engines
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    Accessory drive belt
     
    Alternator electrical connectors
     
    Power steering line clip
     
    Alternator

    Click image to see an enlarged view

    Fig. 3.5L Engine alternator and mounting bolts

     

  4.  

To install:

  1. Install or connect the following:

    Alternator. Tighten the nuts to 22 ft. lbs. (30 Nm) and the bolts to 37 ft. lbs. (50 Nm).
     
    Alternator electrical connector. Tighten the nut to 15 ft. lbs. (20 Nm).
     
    Power steering line clip. Tighten the nut to 44 inch. lbs. (5 Nm).
     
    Accessory drive belt
     
    Negative battery cable
     

  2.  

 
label.common.footer.alt.autozoneLogo