Cherokee, Grand Cherokee, 1999-2005

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 the negative battery cable.
  2.  
  3. Remove the battery.
  4.  
  5. Remove the drive belt.
  6.  
  7. Remove any splash shielding for easier access to the alternator.
  8.  



Click image to see an enlarged view

Fig. For easiest access to the alternator assembly, first remove the splash shield mounting fasteners ...



Click image to see an enlarged view

Fig. ... then swing it out of the way for access to the alternator assembly



Click image to see an enlarged view

Fig. View of the alternator electrical connections-(A) battery positive, (B) field terminals, (C) wire harness hold down, (D) ground terminal

  1. Tag and disengage the alternator wiring.
  2.  
  3. Unfasten the alternator upper and lower bolts.
  4.  

The alternator can be removed from above by taking it off its mountings, moving it rearward and lifting it out, being careful to gently move aside the refrigerant hoses, if equipped with A/C.

New alternators should come with a new bushing. If not, the old bushing should be used. Push out the pivot bushing as illustrated.



Click image to see an enlarged view

Fig. Mount a C-clamp and 18mm socket on the alternator pivot bushing ...



Click image to see an enlarged view

Fig. ... then compress the C-clamp until it pushes the alternator pivot bushing out

To install:

  1. Mount the alternator to the brackets with the nuts and bolts. Tighten the two mounting bolts and nuts to 40 ft. lbs. (54 Nm).
  2.  
  3. If the alternator and mounting bracket were removed as an assembly, install the assembly into the vehicle.
  4.  
  5. Engage the alternator electrical connections.
  6.  
  7. If removed, install the splash shield.
  8.  
  9. Install the drive belt and attach the negative battery cable.
  10.  

5.7L Engines
  1. Before servicing the vehicle, please familiarize yourself with safety procedures.
  2.  
  3. Disconnect negative battery cable at battery.
  4.  
  5. Remove generator drive belt.
  6.  
  7. Unsnap plastic insulator cap from B+ output terminal.
  8.  
  9. Remove B+ terminal mounting nut at rear of generator. Disconnect terminal from generator.
  10.  
  11. Disconnect field wire connector at rear of generator by pushing on connector tab.
  12.  
  13. Remove 2 generator mounting bolts.
  14.  
  15. Remove generator from vehicle.

    Click image to see an enlarged view

    Fig. Alternator mounting-5.7L engine

  16.  

To install:

  1. Position generator to engine and install 2 mounting bolts.
  2.  
  3. Tighten bolts to 30 ft. lbs. (41 Nm).
  4.  
  5. Snap field wire connector into rear of generator.
  6.  
  7. Install B+ terminal eyelet to generator output stud. Tighten mounting nut.
    WARNING
    Never force a belt over a pulley rim using a screwdriver. The synthetic fiber of the belt can be damaged.


    NOTE
    When installing a serpentine accessory drive belt, the belt MUST be routed correctly. The water pump may 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. Install negative battery cable to battery.
  12.  

Except 5.7L Engine
  1. Before servicing the vehicle, please familiarize yourself with safety procedures.
  2.  
  3. Remove or disconnect the following:
    NOTE
    The 3.7L and 4.7L engines have 1 vertical and 2 horizontal bolts.



    Negative battery cable
     
    Accessory drive belt
     
    Alternator harness connectors
     
    Alternator
     
    Mounting bolts and alternator
     

  4.  

To install:

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

  1. Before servicing the vehicle, please familiarize yourself with safety procedures.
  2.  
  3. Install the alternator and tighten the bolts to the following specifications:

    2.5L and 4.0L engines: 41 ft. lbs. (55 Nm).
     
    3.7L engine: Tighten the horizontal bolts to 42 ft. lbs. (57 Nm), then the vertical bolt to 29 ft. lbs. (40 Nm)
     
    4.7L engine: Vertical bolt and long horizontal bolt to 41 ft. lbs. (56 Nm), short horizontal bolt to 55 ft. lbs. (74 Nm)
     

  4.  
  5. Install or connect the following:

    Alternator harness connectors
     
    Accessory drive belt
     
    Negative battery cable
     

  6.  

 
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