Liberty, Wrangler, 1997-2005

Alternator

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Diagnosis & Testing



The following procedures may be used to diagnose the charging system if:



The check gauges lamp (if equipped) is illuminated with the engine running
 
The voltmeter (if equipped) does not register properly
 
An undercharged or overcharged battery condition occurs.
 

Remember that an undercharged battery is often caused by:



Accessories being left on with the engine not running
 
A faulty or improperly adjusted switch that allows a lamp to stay on.
 

Inspection :The Power train Control Module (PCM) monitors critical input and output circuits of the charging system, making sure they are operational. A Diagnostic Trouble Code (DTC) is assigned to each input and output circuit monitored by the On-Board Diagnostic (OBD) system. Some charging system circuits are checked continuously, and some are checked only under certain conditions.

Perform the following inspections before attaching the scan tool.

  1. Inspect the battery condition.
  2.  
  3. Inspect condition of battery cable terminals, battery posts, connections at engine block, starter solenoid and relay. They should be clean and tight. Repair as required.
  4.  
  5. Inspect all fuses in both the fuse block and Power Distribution Center (PDC) for tightness in receptacles. They should be properly installed and tight. Repair or replace as required.
  6.  
  7. Inspect generator mounting bolts for tightness. Replace or tighten bolts if required.
  8.  
  9. Inspect generator drive belt condition and tension. Tighten or replace belt as required.
  10.  
  11. Inspect automatic belt tensioner (if equipped).
  12.  
  13. Inspect generator electrical connections at generator field, battery output, and ground terminal (if equipped). Also check generator ground wire connection at engine (if equipped). They should all be clean and tight. Repair as required.
  14.  

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. 3.7L 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. The alternator for the 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

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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