Chrysler Caravan/Voyager/Town and Country 1996-1999

Alternator

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TESTING



Voltage Drop Test

See Figure 1

These tests will show the amount of voltage drop across the alternator output wire from the alternator output (B+) terminal to the battery positive post. They will also show the amount of voltage drop from the ground (-) terminal on the alternator.

A voltmeter with a 0-18 volt DC scale should be used for these tests. By repositioning the voltmeter test leads, the point of high resistance (voltage drop) can easily be found. Test points on the alternator can be reached by removing the windshield wiper/motor module assembly. Refer to Chassis Electrical to remove this component.

  1. Before starting the test, make sure the battery is in good condition and is fully charged. Check the conditions of the battery cables.
  2.  
  3. Start the engine, let it warm up to normal operating temperatures, then turn the engine OFF .
  4.  
  5. Connect an engine tachometer, following the manufacturer's directions.
  6.  
  7. Make sure the parking brake is fully engaged.
  8.  
  9. Start the engine, then place the blower on HIGH, and turn on the high beam headlamps and rear window defogger.
  10.  
  11. Bring the engine speed up to 2,400 rpm and hold it there.
  12.  
  13. To test the positive (+) circuitry, perform the following:
    1. Touch the negative (-) lead of the voltmeter directly to the positive battery post.
    2.  
    3. Touch the positive (+) lead of the voltmeter to the B+ output terminal stud on the alternator case (NOT the terminal mounting nut). The voltage should be no higher than 0.6 volt. If the voltage is higher than 0.6 volt, touch the test lead to the terminal mounting stud nut, and then to the wiring connector. If the voltage is now below 0.6 volt, look for dirty, loose or poor connections at this point. Also inspect the condition of the alternator output wire-to-battery bullet connector. A voltage drop test may be performed at each negative (-) ground connection in this circuit to locate the excessive resistance.
    4.  

  14.  
  15. To test the negative (-) ground circuitry, perform the following:
    1. Touch the positive (+) lead of the voltmeter directly to the negative battery post.

      Click image to see an enlarged view

      Fig. Fig. 1: Locations of the alternator terminals

    2.  
    3. Touch the negative lead of the voltmeter to the alternator case (NOT the terminal mounting nut). The voltage should be no higher than 0.3 volt. If the voltage is higher than 0.3 volt, touch the test lead to the alternator case, and then to the engine block. If the voltage is now below 0.3 volt, look for dirty, loose or poor connections at this point. A voltage drop test may be performed at each connection in this circuit to locate excessive resistance.
    4.  

  16.  
  17. This test can also be performed between the alternator case and the engine. If the test voltage is higher than 0.3 volt, check for corrosion at the alternator mounting points or loose alternator mounting.
  18.  

Output Voltage Test
  1. Determine if any Diagnostic Trouble Codes (DTC'S) exist, as outlined in Driveability & Emissions Controls .
  2.  
  3. Before starting the test, make sure the battery is in good condition and is fully charged. Check the conditions of the battery cables.
  4.  
  5. Perform the voltage drop test to ensure clean and tight alternator/battery electrical connections.
  6.  
  7. Be sure the alternator drive belt is properly tensioned, as outlined in General Information & Maintenance .
  8.  
  9. A volt/amp tester equipped with both a battery load control (carbon pile rheostat) and an inductive-type pickup clamp (ammeter probe) will be used for this test. Make sure to follow all directions supplied with the tester. If you are using a tester equipped with an inductive-type clamp, you don't have to remove the wiring from the alternator.
  10.  
  11. Start the engine and let it run until it reaches normal operating temperature, then shut the engine OFF .
  12.  
  13. Make sure all electrical accessories and lights are turned OFF.
  14.  
  15. Connect the volt/amp tester leads to the battery. Be sure the carbon pile rheostat control is in the OPEN or OFF position before connecting the leads.
  16.  
  17. Connect the inductive clamp (ammeter probe), following the instructions supplied with the test equipment.
  18.  
  19. If a volt/amp tester is not equipped with an engine tachometer, connect a separate tachometer to the engine.
  20.  
  21. Fully engage the parking brake.
  22.  
  23. Start the engine, then bring the engine speed up to 2,500 rpm.
  24.  


WARNING
This load test must be performed within 15 seconds to prevent damage to the test equipment!

  1. With the engine speed held at 2,500 rpm, slowly adjust the rheostat control (load) on the tester to get the highest amperage reading. Do not let the voltage drop below 12 volts. Record the reading.
  2.  

On certain brands of test equipment, this load will be applied automatically. Be sure to read the operating manual supplied with the test equipment before performing the test.

  1. The ammeter reading must meet the minimum test amps specification of 86 amps.
  2.  
  3. Rotate the load control to the OFF position.
  4.  
  5. Continue holding the engine speed at 2,500 rpm. If the Electronic Voltage Regulator (EVR) circuitry is OK, the amperage should drop below 15-20 amps. With all of the electrical accessories and vehicle lighting off, this could take several minutes of engine operation.
  6.  
  7. After the procedure is complete, remove the volt/amp tester.
  8.  

REMOVAL & INSTALLATION



2.4L Engine

See Figure 2



Click image to see an enlarged view

Fig. Fig. 2: Alternator removal-2.4L engine

  1. Disconnect the negative battery cable.
  2.  
  3. Remove the accessory drive belt.
  4.  
  5. Unplug the push-in field wire connector from behind the alternator.
  6.  
  7. Remove the B+ nut and wire from behind the alternator.
  8.  
  9. Remove the nut securing the top of the alternator to the adjuster bolt (a.k.a T-bolt).
  10.  
  11. Remove the alternator pivot nut and bolt, located below the alternator.
  12.  
  13. Remove the alternator from the vehicle.
  14.  

To install:
  1. Install the alternator into position on the vehicle's engine.
  2.  
  3. Install, but do not tighten, the alternator pivot nut and bolt.
  4.  
  5. Install the nut securing the top of the alternator to the adjuster bolt.
  6.  
  7. Connect the B+ wire and tighten the retaining nut to 75 inch lbs. (9 Nm).
  8.  
  9. Plug in the push-in field wire connector onto the back of the alternator.
  10.  
  11. Install the accessory drive belt. Be sure the drive belt is correctly routed on the engine and correctly seated on all of the pulleys, especially the alternator.
  12.  
  13. Adjust the drive belt and tighten the adjuster/locking bolt to 40 ft. lbs. (54 Nm).
  14.  
  15. Tighten the pivot bolt to 40 ft. lbs. (54 Nm).
  16.  
  17. Reconnect the negative battery cable.
  18.  
  19. Verify the charging rate of the alternator.
  20.  

3.0L Engine

See Figures 3, 4, 5, 6 and 7

  1. Disconnect the negative battery cable.
  2.  
  3. Remove the windshield wiper/motor module assembly. Refer to Chassis Electrical for this procedure.
  4.  



Click image to see an enlarged view

Fig. Fig. 3: Rotate the accessory drive belt tensioner clockwise, and slip the belt off of the pulley ...



Click image to see an enlarged view

Fig. Fig. 4: ... then remove the bolt securing the top of the alternator to the bracket ...



Click image to see an enlarged view

Fig. Fig. 5: ... as well as the bottom bolt securing the alternator to the lower pivot bracket

  1. Remove the accessory drive belt from the alternator.
  2.  
  3. Remove the bolt securing the top of the alternator to the mounting bracket.
  4.  
  5. Remove the bolt securing the bottom of the alternator to the lower pivot bracket.
  6.  



Click image to see an enlarged view

Fig. Fig. 6: With both mounting bolts removed, lift and rotate the alternator to access the wiring harness



Click image to see an enlarged view

Fig. Fig. 7: Disconnect the wiring from behind the alternator

  1. While holding the alternator, unplug the push-in field wire connector from behind the alternator.
  2.  
  3. While holding the alternator, remove the B+ nut and wire from behind the alternator.
  4.  
  5. Remove the alternator from the vehicle.
  6.  

To install:
  1. Hold the alternator in position near the mounting bracket, then connect the B+ wire and tighten the retaining nut to 75 inch lbs. (9 Nm).
  2.  
  3. Plug in the push-in field wire connector onto the back of the alternator.
  4.  
  5. Place the alternator into position on the mounting bracket, then install the bolt securing the bottom of the alternator to the lower pivot bracket.
  6.  
  7. Install the bolt securing the top of the alternator to the mounting bracket. Tighten the upper and lower alternator bolts to 40 ft. lbs. (54 Nm).
  8.  
  9. Install the accessory drive belt. Be sure the drive belt is correctly routed on the engine and correctly seated on all of the pulleys.
  10.  
  11. Install the windshield wiper/motor module assembly.
  12.  
  13. Reconnect the negative battery cable.
  14.  
  15. Verify the charging rate of the alternator.
  16.  

3.3L and 3.8L Engines

See Figures 8, 9 and 10

  1. Disconnect the negative battery cable.
  2.  
  3. Remove the windshield wiper/motor module assembly. Refer to Chassis Electrical for this procedure.
  4.  
  5. Remove the accessory drive belt.
  6.  
  7. Remove the bolt securing the top of the alternator mounting bracket to the engine air intake plenum.
  8.  



Click image to see an enlarged view

Fig. Fig. 8: Alternator mounting bracket

  1. Remove the bolts securing the outside of the alternator mounting bracket to the alternator mounting plate.
  2.  
  3. Remove the bolt securing the top of the alternator to the mounting bracket.
  4.  
  5. Remove the alternator mounting bracket from the vehicle.
  6.  
  7. Rotate the alternator toward the dash panel.
  8.  
  9. Unplug the push-in field wire connector from behind the alternator.
  10.  
  11. Remove the B+ nut and wire from behind the alternator.
  12.  



Click image to see an enlarged view

Fig. Fig. 9: Alternator pivot bolt



Click image to see an enlarged view

Fig. Fig. 10: Alternator removal-3.3L and 3.8L engines

  1. Remove the bolt securing the bottom of the alternator to the lower pivot bracket.
  2.  
  3. Remove the alternator from the vehicle.
  4.  

To install:
  1. Install the alternator into position on the vehicle's engine.
  2.  
  3. Install the bolt securing the bottom of the alternator to the lower pivot bracket.
  4.  
  5. Connect the B+ wire and tighten the retaining nut to 75 inch lbs. (9 Nm).
  6.  
  7. Plug in the push-in field wire connector onto the back of the alternator.
  8.  
  9. Rotate the alternator forward away from the dash panel.
  10.  
  11. Install the alternator mounting bracket in position on the vehicle.
  12.  
  13. Install the bolt to secure the top of the alternator to the mounting bracket.
  14.  
  15. Install the bolts to secure the outside of the alternator mounting bracket to the alternator mounting plate.
  16.  
  17. Install the bolt to secure the top of the alternator mounting bracket to the engine air intake plenum.
  18.  
  19. Tighten all of the alternator mounting bolts to 40 ft. lbs. (54 Nm).
  20.  
  21. Install the accessory drive belt. Be sure the drive belt is correctly routed on the engine and correctly seated on all of the pulleys.
  22.  
  23. Install the windshield wiper/motor module assembly.
  24.  
  25. Reconnect the negative battery cable.
  26.  
  27. Verify the charging rate of the alternator.
  28.  

 
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