GM Malibu/Cutlass 1997-2000

Alternator

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TESTING



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 DC volts, 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.  

No-Load Test
  1. Connect a tachometer to the engine.
  2.  


CAUTION
Ensure that the transmission is in P and the emergency brake is set. Blocking a wheel is optional, but is highly recommended as an added safety measure.

  1. Turn off all electrical loads (radio, blower motor, wipers, etc.)
  2.  
  3. Start the engine and increase engine speed to approximately 1500 rpm.
  4.  
  5. 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.
  6.  
  7. 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.
  8.  


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 guide, 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.

  1. If the voltage is within specifications, proceed to the next test.
  2.  

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.
  8.  


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 guide, 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.

REMOVAL & INSTALLATION



2.4L Engine


Click image to see an enlarged view

Fig. The alternator on the 2.4L engine is secured by 2 bolts and one nut, shown here on the stud end bolt

  1. Disconnect the negative battery cable.
  2.  


CAUTION
Failure to disconnect the negative cable may result in injury from the positive battery lead at the alternator, and may short the alternator and regulator during the removal process.

  1. Remove the serpentine belt from the alternator, as outlined in of this guide.
  2.  
  3. Remove the alternator mounting stud and bolt from above the alternator.
  4.  
  5. Loosen the bolt on the front of alternator and gently pivot alternator back away from engine.
  6.  
  7. Detach the electrical connections from the alternator.
  8.  
  9. Remove the bolt from the front of alternator, then remove the alternator.
  10.  

To install:


NOTE
If replacing the alternator make sure the pulley on the replacement alternator is the same as the one you removed. Check the number of ribs, the width of the pulley and the diameter. Various pulleys are used for many applications. Damage to the serpentine belt may occur from incorrect pulley size.

  1. Attach the electrical connectors to the alternator.
  2.  
  3. Align the bolt holes in the alternator with the mounting holes on the engine. Insert the bolts and stud and tighten by hand.
  4.  
  5. After all of the retainers are installed, tighten them to 37 ft. lbs. (50 Nm).
  6.  
  7. Install the serpentine belt. Refer to of this guide.
  8.  
  9. Connect the negative battery cable.
  10.  

3.1L Engine


Click image to see an enlarged view

Fig. The alternator on the 3.1L engine is fastened in three places

  1. Disconnect the negative battery cable.
  2.  


CAUTION
Failure to disconnect the negative cable may result in injury from the positive battery lead at the alternator, and may short the alternator and regulator during the removal process.

  1. Remove the serpentine belt from the alternator, as outlined in of this guide.
  2.  
  3. Unplug the electrical connector from the alternator.
  4.  



Click image to see an enlarged view

Fig. This electrical connector can be accessed easily without loosening or removing any fasteners

  1. Unfasten the bolt/screw from the front of the alternator.
  2.  



Click image to see an enlarged view

Fig. Remove the bolt from the front of the alternator . . .

  1. Remove the bolt from the top of the alternator.
  2.  



Click image to see an enlarged view

Fig. . . . then remove the bolt and nut located on the top of the alternator. Note that a swivel extension may come in handy for nut removal

  1. Remove the nut located near the rear of the alternator.
  2.  
  3. Remove the power steering line clip.
  4.  
  5. Remove the alternator from its mounting for accessibility to the battery electrical connection.
  6.  



Click image to see an enlarged view

Fig. The battery electrical connection can be loosened by a wrench, then removed by hand

  1. Unfasten the nut and battery positive lead from the alternator terminal.
  2.  
  3. Remove the alternator from the vehicle.
  4.  



Click image to see an enlarged view

Fig. The alternator's rear mounting hole is slotted for easy removal and alignment on re-installation

To install:

  1. Attach the battery positive lead and the nut to the alternator output terminal. Tighten the nut to 15 ft. lbs. (20 Nm).
  2.  
  3. Position the alternator onto the mounting bracket.
  4.  
  5. Install the bolts to the alternator. Tighten to 37 ft. lbs. (50 Nm).
  6.  
  7. Fasten the power steering gear pipe clip and nut. Tighten to 22 ft. lbs. (30 Nm).
  8.  
  9. Attach the electrical connector to the alternator. The connector will snap into place when it is correctly installed.
  10.  
  11. Install the drive belt on the alternator as outlined in of this guide.
  12.  
  13. Connect the negative battery cable.
  14.  

 
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