Liberty, Wrangler 2006-2007

Alternator

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Diagnosis & Testing



Load Test
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. 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).
  4.  
  5. Increase and hold engine speed to 2000 RPM.
  6.  
  7. Measure the voltage reading at the battery.
  8.  
  9. 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.

  10.  

No Load Test
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. 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.

  4.  
  5. Turn off all electrical loads (radio, blower motor, wipers, etc.)
  6.  
  7. Start the engine and increase engine speed to approximately 1500 RPM.
  8.  
  9. 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.
  10.  
  11. 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.

  12.  
  13. If the voltage is within specifications, proceed to the next test.
  14.  

Voltage Test
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Make sure the engine is OFF , and turn the headlights on for 15-20 seconds to remove any surface charge from the battery.
  4.  
  5. Using a DVOM set to volts DC, probe across the battery terminals.
  6.  
  7. Measure the battery voltage.
  8.  
  9. Write down the voltage reading and proceed to the next test.
  10.  

Removal & Installation



  1. Disconnect negative battery cable at battery.
  2.  
  3. Remove alternator drive belt.
  4.  
  5. Remove alternator pivot and mounting bolts/nut and position generator for access to wire connectors.
  6.  
  7. If equipped, unsnap plastic cover from B+ terminal.
  8.  
  9. Remove B+ cable output terminal mounting nut at rear of generator, or Disconnect terminal from alternator.
  10.  
  11. Disconnect field wire connector at rear of alternator by pushing on connector tab.
  12.  
  13. Remove generator from vehicle
  14.  

To install:

  1. Position generator to engine and snap field wire connector into rear of alternator.
  2.  
  3. Install B+ terminal to alternator mounting stud. Tighten mounting nut.
  4.  
  5. If equipped, snap plastic cover to B+ terminal.
  6.  
  7. Install alternator mounting fasteners and tighten
    CAUTION
    Never force a belt over a pulley rim using a screwdriver. The synthetic fiber of the belt can be damaged


    CAUTION
    When installing a serpentine accessory drive belt, the belt MUST be routed correctly. The water pump will be rotating in the wrong direction if the belt is installed incorrectly, causing the engine to overheat.

  8.  
  9. Install generator drive belt.
  10.  
  11. Tighten alternator hardware as follows:

    Generator upper mounting bolt-All engines-41 ft. lbs. (55 Nm)
     
    Generator lower mounting bolt-All engines-41 ft. lbs. (55 Nm)
     
    Battery terminal nut-75 inch lbs. (8.5 Nm)
     
    Ground terminal nut-75 inch lbs. (8.5 Nm)
     
    Harness hold-down nut-75 inch lbs. (8.5 Nm)
     
    Field terminal nuts-25 inch lbs. (2.8 Nm)
     

  12.  
  13. Install negative battery cable to battery.

    Click image to see an enlarged view

    Fig. 2.4L engine alternator mounting



    Click image to see an enlarged view

    Fig. 4.0L engine alternator mounting

  14.  


WARNING
Disconnect the negative cable from the battery before removing the battery output wire (B+ wire) from the alternator. Failure to do so can result in injury or damage to the electrical system.

Diesel Engine


Click image to see an enlarged view

Fig. Alternator mounting-Liberty with diesel engine


CAUTION
Disconnect negative cable from the battery before removing battery output wire from the alternator. Failure to do so can result in injury.


CAUTION
Never force a belt over a pulley rim using a screwdriver. The synthetic fiber of the belt can be damaged.


CAUTION
When installing a serpentine accessory drive belt, the belt MUST be routed correctly. The water pump will be rotating in the wrong direction if the belt is installed incorrectly, causing the engine to overheat. Refer to belt routing label in engine compartment.

  1. Disconnect and isolate negative battery cable.
  2.  
  3. Remove engine oil fill cap and engine oil dipstick.
  4.  
  5. Remove plastic decorative engine cover. Cover snaps onto engine.
  6.  
  7. Remove generator drive belt.
  8.  
  9. Remove protective plastic cover from B+ stud at top of generator.
  10.  
  11. Remove nut securing battery output cable to B+ terminal at top of generator .
  12.  
  13. Unplug field terminal connector at rear of generator.
  14.  
  15. Loosen support bracket bolts and nut.
  16.  
  17. Remove 2 alternator mounting bolts
  18.  
  19. Remove alternator from vehicle.
  20.  

To install:

  1. Position alternator to engine.
  2.  
  3. Install alternator mounting bolts/nuts.
  4.  
  5. Connect field terminal connector at rear of alternator.
  6.  
  7. Install battery output cable and nut to B+ terminal at top of alternator.
  8.  
  9. Install protective plastic cover to B+ stud at top of generator.
    CAUTION
    Never force a belt over a pulley rim using a screwdriver. The synthetic fiber of the belt can be damaged.


    CAUTION
    When installing a serpentine accessory drive belt, the belt MUST be routed correctly. The water pump will be rotating in the wrong direction if the belt is installed incorrectly, causing the engine to overheat. Refer to belt routing label in engine compartment.

  10.  
  11. Install alternator drive belt.
  12.  
  13. Install engine oil fill cap and engine oil dipstick.
  14.  
  15. Install plastic decorative engine cover. Cover snaps onto engine.
  16.  
  17. Connect negative battery cable.
  18.  
  19. Check charging system for proper operation.
  20.  

Gasoline Engines


Click image to see an enlarged view

Fig. 3.7L engine alternator mounting


CAUTION
Disconnect negative cable from the battery before removing battery output wire from the alternator. Failure to do so can result in injury.

  1. Disconnect and isolate negative battery cable at battery.
    CAUTION
    Never force a belt over a pulley rim using a screwdriver. The synthetic fiber of the belt can be damaged.


    CAUTION
    When installing a serpentine accessory drive belt, the belt MUST be routed correctly. The water pump will be rotating in the wrong direction if the belt is installed incorrectly, causing the engine to overheat. Refer to belt routing label in engine compartment.

  2.  
  3. Remove alternator drive belt.
  4.  
  5. Unsnap plastic protective cover from B+ mounting stud.
  6.  
  7. Remove B+ terminal mounting nut at top of alternator.
  8.  
  9. Disconnect field wire electrical connector at rear of alternator by pushing on connector tab.
  10.  
  11. 2.4L Engine: Remove 2 generator mounting bolts .
  12.  
  13. 3.7L Engine: Remove 1 vertical generator mounting bolt and 2 horizontal mounting bolts.
  14.  
  15. Remove alternator from vehicle.

    Click image to see an enlarged view

    Fig. The generator for the 2.4L engine



    Click image to see an enlarged view

    Fig. The generator for the 3.7L engine

  16.  

To install:

  1. 2.4L Engine: Position alternator to engine and install 2 mounting bolts.
  2.  
  3. 3.7L Engine: Position alternator to engine and install 3 mounting bolts. Tighten 2 horizontal mounting bolts to specified torque. Tighten 1 vertical mounting bolt to specified torque.
  4.  
  5. Snap field wire connector into rear of generator.
  6.  
  7. Install B+ terminal and nut to alternator mounting stud.
  8.  
  9. Snap plastic protective cover to B+ terminal.
    CAUTION
    Never force a belt over a pulley rim using a screwdriver. The synthetic fiber of the belt can be damaged.


    CAUTION
    When installing a serpentine accessory drive belt, the belt MUST be routed correctly. The water pump will be rotating in the wrong direction if the belt is installed incorrectly, causing the engine to overheat. Refer to belt routing label in engine compartment.

  10.  
  11. Install drive belt.
  12.  
  13. Install negative battery cable to battery.
  14.  

 
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