M.Y. 1995

Check battery electrolyte level and voltage
1. Check the electrolyte quantity of each cell. If under the lower level, replace the battery (or add distilled water if possible). Check the charging system
2. Measure the battery voltage between the terminals negative (-) and positive (+) of the battery.
  Standard voltage:
  
  SC300: 12.5 - 12.7 V at 20° C (68° F)
  
  Fig 2: Measuring Battery Voltage Between Terminals Negative And Positive
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  HINT:
  - Before measuring the voltage, turn the ignition switch to LOCK and turn off the electrical systems (headlight, blower motor, rear defogger etc.) for 60 seconds to remove the surface charge.
  - If the vehicle has been running, wait 5 minutes or more after the vehicle stops before measuring the battery voltage.
  If the voltage is less than specification, charge the battery.
  
  HINT: Check the indicator as shown in the illustration.
  
  Fig 3: Identifying Indicators
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Check battery terminals and fuses

Fig 4: Battery Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. Check that the battery terminals are not loose or corroded.
2. Check the fusible links and fuses for continuity
  H-fuse:
  
  AlT 120A
  
  AM1 100A
  
  AM2 30A
  
  M-Fuse:
  
  IG SW 40A
  
  Fuse:
  
  INJ 30A
  
  IGN 7.5A
  
  ENGINE 7.5A
Inspect drive belt
HINT: A belt tensioner is used, so checking the belt tension is not necessary

Fig 5: Checking Drive Belt
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. Visually check the drive belt for excessive wear, frayed cords, etc.
  If necessary, replace the drive belt.
  
  HINT:
  - Cracks on rib side of a drive belt are considered acceptable. If the drive belt has chunks missing from the ribs, it should be replaced.
  - The drive belt tension can be released by turning the belt tensioner clockwise.
2. Check the belt tension operation.
  
  Fig 7: Checking That Belt Tensioner
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  - Check that the belt tensioner moves downward when the drive belt is pressed down at the points indicated in the illustration with approx. 98 N (10 kgf, 22.0 lbf) of force.
  - Check the alignment of the belt tensioner pulley to make sure the drive belt has not slipped off the pulley.
    If necessary, replace the belt tensioner.
  - Check that the arrow mark on the belt tensioner falls within area A of the scale.
    If it is outside area A, replace the drive belt.
  - When a new belt is installed, it should be within area B. If not, the drive belt is not installed correctly.
  - After installing a belt, check that it fits properly in the ribbed grooves.
  - Check by hand to confirm that the belt has not slipped out of the groove on the bottom of the pulley.
Remove engine under cover
Visually check generator wiring and listen for abnormal noises

Fig 10: Checking Generator Wiring
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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.
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.
Inspect charging circuit without load

Fig 11: Inspect Charging Circuit Without Load
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT: If a battery/generator tester is available, connect the tester to the charging circuit as per manufacturer's instructions.
1. If a tester is not available, connect a voltmeter and ammeter to the charging circuit as follows:
  - Disconnect the wire from terminals 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 alternator.
  - 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:
  
  Fig 12: Checking Charging
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  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:
  
  13.6 - 14.8 V at 25° C (77° F)
  
  13.2 - 14.0 V at 115° C (239° F)
  
  If the voltmeter reading is greater than standard voltage, replace the voltage regulator.
  
  If the voltmeter reading is less than standard voltage, check the voltage regulator and generator as follows
  
  Fig 13: Locating Terminal F
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  - Remove the engine under cover.
  - With terminal F grounded, start the engine and check the voltmeter reading of terminal B.
  - If the voltmeter reading is greater than standard voltage, replace the voltage regulator.
  - Reinstall the engine under cover.
Inspect charging circuit with load

Fig 15: Amperage 30 Or More
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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 standard amperage, repair the generator.
  
  HINT: With the battery fully charged, the indication will sometimes be less than standard amperage
Reinstall engine under cover