Volkswagen Touareg 2004-06

Alternator

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Diagnosis & Testing



Alternator 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. Further testing, which is not covered by this book, 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.

  10.  

Alternator 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. Further testing, which is not covered by this book, 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.

  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



3.2L Engines
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Disconnect the battery.
  4.  
  5. Unplug the electrical connector from the back of the alternator.
  6.  
  7. Remove the cap from the positive terminal on the alternator and remove the nut securing the cable.
  8.  
  9. On water cooled alternators, clamp the coolant hoses shut. Remove the bolt securing the coolant pipes to the alternator and pull it away from the alternator.
  10.  
  11. On air cooled alternators, remove the air guide over the radiator.
  12.  
  13. Mark the direction of rotation on the belt.
  14.  
  15. Screw a M8x50 bolt into the threaded hole of the tensioner to release tension on the belt. Screw the bolt in only far enough to allow removal of the belt.
  16.  
  17. Remove the 3 bolts securing the tensioner, then remove it together with the belt.
  18.  
  19. Remove the 2 bolts securing the alternator, then remove it from the engine.
  20.  

To install:

  1. Drive the threaded sleeves out of the alternator housing 4mm towards the rear of the alternator.
  2.  
  3. Remaining installation is the reverse of removal. Observe the following tightening torques:
    NOTE
    Be sure to reinstall the belt in the proper direction of rotation and to remove the belt tension release bolt. On water cooled alternators, check the coolant level.



    Alternator bracket and mounting bolts: 15 ft. lbs. (20 Nm)
     
    Tensioner mounting bolts: 15 ft. lbs. (20 Nm)
     
    Coolant pipe: 7 ft. lbs. (9 Nm)
     
    Positive terminal nut: 11 ft. lbs. (15 Nm)
     



    Click image to see an enlarged view

    Fig. Use a M8x50 bolt to release tension on the belt-3.2L engines



    Click image to see an enlarged view

    Fig. Tensioner retaining bolts-3.2L engines



    Click image to see an enlarged view

    Fig. Alternator mounting bolts-3.2L engines

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4.2L Engines
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Disconnect the battery.
  4.  
  5. Remove the engine assembly.
  6.  
  7. Mark the direction of rotation on the belt.
  8.  
  9. Rotate the tensioner using a 19mm wrench and secure it in the released position using tool T10060A or a similar sized pin punch. Remove the belt.
  10.  
  11. Unplug the electrical connector from the back of the alternator.
  12.  
  13. Remove the cap from the positive terminal on the alternator and remove the nut securing the cable.
  14.  
  15. Remove the bolt securing the coolant lines on the alternator, then pull the lines away from it.
  16.  
  17. Remove the 2 bolts securing the alternator to the engine.
  18.  

To install:

  1. Installation is the reverse of removal. Observe the following tightening torques:
    NOTE
    Be sure to reinstall the belt in the proper direction of rotation and to remove the belt tension release tool. Use new O-rings on the coolant pipes and check the coolant level.



    Alternator bracket and mounting bolts: 15 ft. lbs. (20 Nm)
     
    Tensioner mounting bolts: 15 ft. lbs. (20 Nm)
     
    Coolant pipe: 7 ft. lbs. (9 Nm)
     
    Positive terminal nut: 11 ft. lbs. (15 Nm)
     



    Click image to see an enlarged view

    Fig. Alternator mounting bolts-4.2L engines

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