Scion 2005-06

Alternator

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Diagnosis & Testing



1.5L Engine

NOTE
Before testing the charging system, make sure the battery is operating properly and the drive belt is in good condition.

  1. Check the charge warning light circuit, as follows:
    1. Turn the ignition switch ON. Check that the charge warning light comes on.
    2.  
    3. Start the engine. Check that the light goes off.
      NOTE
      If the light does not operate as specified, troubleshoot the charge warning light circuit.

    4.  

  2.  
  3. Check the charging system, without load, as follows:
    1. Connect a voltmeter and ammeter as follows:

      Disconnect the wire from terminal B of the generator and connect it to the negative (-) lead of the ammeter.
       
      Connect the positive (+) lead of the ammeter to terminal B of the generator.
       
      Connect the positive (+) lead of the voltmeter to terminal B of the generator.
       
      Ground the negative (-) lead of the voltmeter.

      Click image to see an enlarged view

      Fig. Test connections for the charging system-1.5L engine

       

    2.  
    3. Check the charging circuit. Check the readings on both the ammeter and voltmeter with the engine running at 2000 rpm, and compare with the following:
      NOTE
      If the voltmeter reading is more than the standard voltage, replace the voltage regulator. If the voltmeter reading is less than the standard voltage, check the voltage regulator and alternator.



      Standard amperage: 10 A or less
       
      Standard voltage: 12.9 to 14.9 V
       

    4.  

  4.  
  5. Check the charging system, with load, as follows:
    1. With the engine running at 2,000 rpm, turn on the high beam headlights and turn the heater blower switch to the -HI- position.
    2.  
    3. Check the reading on the ammeter. The standard amperage is 30 A or more
      NOTE
      If the ammeter reading is less than the standard amperage, repair the generator. If the battery is fully charged, the indication will sometimes be less than the standard amperage.

    4.  

  6.  

2.4L Engine

NOTE
Before testing the charging system, make sure the battery is operating properly and the drive belt is in good condition.

  1. Check the charge warning light circuit, as follows:
    1. Turn the ignition switch to ON. Check that the charge warning light comes on.
    2.  
    3. Start the engine and check that the light goes off.
    4.  
    5. If the light does not operate as specified, troubleshoot the charge warning light circuit.
    6.  

  2.  
  3. Check the charging system, without load, as follows:
    1. If a tester is not available, connect a voltmeter and ammeter to the charging circuit as follows:

      Disconnect the wire from terminal B of the generator, then connect it to the negative (-) lead of the ammeter.
       
      Connect the positive (+) lead of the ammeter to terminal B of the generator.
       
      Connect the positive (+) lead of the voltmeter to terminal B of the generator.

      Click image to see an enlarged view

      Fig. Charging system test connections-2.4L engine

       

    2.  
    3. Ground the negative (-) lead of the voltmeter.
    4.  
    5. Inspect the charging circuit. Keep the engine speed at 2,000 rpm and check the reading on the ammeter and voltmeter. Compare with the following specifications:

      10 A or less for amperage
       
      13.2 to 14.8 V for voltage
       

    6.  

  4.  
  5. Check the charging system, with load, as follows:
    1. With the engine running at 2,000 rpm, turn the high beam headlights ON and turn the heater blower switch to the -HI- position.
    2.  
    3. Check the reading on the ammeter. It should read 30 or more amps.

      If the ammeter reading is less than the standard amperage, repair the generator.
       
      If the battery is fully charged, the indication will sometimes be less than the standard amperage.
       

    4.  

  6.  

Removal & Installation



1.5L Engine
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Disconnect the alternator wiring connections.
  6.  
  7. Loosen, but do not remove the alternator mounting bolts.
  8.  
  9. Release the alternator drive belt tension and remove the belt.
  10.  
  11. Remove the top alternator mounting bolt and fan belt adjusting bar.
  12.  
  13. Remove the bottom alternator mounting bolt and alternator.
  14.  

To install:

  1. Temporarily install the alternator with the bottom mounting bolt.
  2.  
  3. Install the fan belt adjusting bar with the top alternator mounting bolt. Tighten fan belt adjusting bar nuts to 8 ft. lbs. (11 Nm).
  4.  
  5. Install the alternator drive belt and push the adjusting bar towards the vehicle front to adjust the tension.
    WARNING
    Do not insert the adjusting bar between the oil control valve and alternator as it could damage the oil control valve.

  6.  
  7. Tighten the top mounting bolt to 14 ft. lbs. (19 Nm). Tighten the bottom mounting bolt to 40 ft. lbs. (54 Nm).
  8.  
  9. Connect the alternator wiring connections.
  10.  
  11. Connect the negative battery cable.
  12.  

 
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