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On-Vehicle Testing: Battery

CAUTION:
  • Check that the battery cables are connected to the correct terminals.
  • Disconnect the battery cables when the battery is given a quick charge.
  • Do not perform tests with a high voltage insulation resistance tester.
  • Never disconnect the battery while the engine is running.
  1. Check the electrolyte quantity of each cell.

    Maintenance-Free Battery:

    If under the lower level, replace the battery (or add distilled water if possible). Check the charging system.

    Except Maintenance-Free Battery:

    If under the lower level, add distilled water.

  2. Except Maintenance-Free Battery:
    Fig 1: Except Maintenance-Free Battery
    G00490157Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    Check battery specific gravity

    Check the specific gravity of each cell.

    Standard specific gravity: 1.25-1.29 at 20° C (68° F) 

    If the specific gravity is less than specification, charge the battery.

  3. Maintenance-Free Battery:
    Fig 2: Maintenance-Free Battery:
    G00490158Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    Check battery specific gravity

    1. After having drive the vehicle and in the case that 20 minutes have not passed after having stopped the engine, turn the ignition switch ON and turn on the electrical system (headlight, blower motor, rear defogger etc.) for 60 seconds to remove the surface charge.
    2. Turn the ignition switch OFF and turn off the electrical systems.
    3. Measure the battery voltage between the negative (-) and positive (+) terminals of the battery.

      Standard voltage: 12.5-12.9 V at 20° C (68° F) 

      If the voltage is less than specification, charge the battery.

  4. Check battery terminals, fusible link and fuses
    1. Check that the battery terminals are not loose or corroded.

      If the terminals are corroded, clean the terminals.

    2. Check the fusible link, H-fuses and fuses for continuity.
  5. Inspect drive belts
    1. Visually check the drive belt for cracks, oiliness or wear.

      Check that the belt does not touch the bottom of the pulley groove.

      Fig 3: Checking Drive Belt
      G00490167Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Using a belt tension gauge, measure the belt tension.
      Fig 4: Measuring Belt Tension
      G00490168Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Belt tension gauge:

      Nippondenso BTG-20 (95506-00020)

      Boroughs No. BT-33-73F

      DRIVE BELT TENSION

      New belt 100-150 lb.ft
      Used belt 60-100 lb.ft

      If the belt tension is not as specified, adjust it.

      HINT:

      • "New belt" refers to a belt which has been used less than 5 minutes on a running engine.
      • "Used belt" refers to a belt which has been used on a running engine for 5 minutes or more.
      • After installing a belt, run the engine for about 5 minutes and recheck the belt tension.
  6. Visually check generator wiring and listen for abnormal noises
    1. Check that the wiring is in good condition.
    2. Check that there is no abnormal noise from the generator while the engine is running.
  7. Check charge warning light circuit
    1. Warm up the engine and then turn it off.
    2. Turn off all accessories.
    3. Turn the ignition switch "ON". Check that the charge warning light is lit.
    4. Start the engine. Check that the light goes off.

      If the light does not go off as specified, troubleshoot the charge light circuit.

  8. Inspect charging circuit without load

    HINT: If a battery/generator tester is available, connect the tester to the charging circuit as per manufacturer's instructions.

    Fig 5: Inspect Charging Circuit Without Load
    G00490123Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    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 and connect it to the negative (-) probe of the ammeter.
      • Connect the positive (+) probe of the ammeter to terminal B of the generator.
      • Connect the positive (+) probe of the voltmeter to terminal B of the generator.
      • Ground the negative (-) probe of the voltmeter.
    2. Check the charging circuit as follows:

      With the engine running from idling to 2,000 rpm, check the reading on the ammeter and voltmeter.

      Standard amperage: 10 A or less 

      Standard voltage: 

      At 25° C (77° F): 14.0 - 15.1V 

      At 115° C (239° F): 13.5 - 14.3 V 

      If the voltmeter reading is more than standard voltage, replace the voltage regulator.

      If the voltmeter reading is less than standard voltage, check the voltage regulator and generator as follows:

      • With terminal F grounded, start the engine and check the voltmeter reading of terminal B.
      • If the voltmeter reading is more than standard voltage, replace the voltage regulator.
      • If the voltmeter reading is less than standard voltage, check the generator.
      3. Fig 6: Locating Terminal F
      G00490169Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  9. Inspect charging circuit with load
    1. With the engine running at 2,000 rpm, turn on the high beam headlights and place the heater blower switch at "HI".
    2. Check the reading on the ammeter.

      Standard amperage: 30 A or more 

      If the ammeter reading is less than the standard amperage, repair the alternator.

      HINT: If the battery is fully charged, the indication will sometimes be less than standard amperage.

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