Charging System on-Vehicle Inpection
ON-VEHICLE INSPECTION
CAUTION:
- Check that the battery cables are connected to the correct terminals.
- Disconnect the battery cables when the battery is given a quick charge.
- Never disconnect the battery while the engine is running.
CHECK BATTERY VOLTAGE
1. If 20 minutes have not passed since the engine was stopped, turn the ignition switch ON and turn on the electrical system (headlamp, 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 - 12.9V at 20°C(68°F)
If the voltage is less than specification, charge the battery.
CHECK THE BATTERY TERMINALS AND FUSES
1. Check that the battery terminals are not loose or corroded.
2. Check the fuses for continuity.
INSPECT DRIVE BELT
1. Visually check the belt for excessive wear, frayed cords etc.
If any defect has been found, replace the drive belt.
NOTE:
Cracks on the rib side of a belt are considered acceptable. If the belt has chunks missing from the ribs, it should be replaced.
2. Measure the drive belt tension and adjust it.
Apply a force of 98N (10kg, 22lb), and measure the deflection between the generator and the water pump pulley.
DEFLECTION
If the belt tension is not as specified, adjust it.
NOTE:
- "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, check that it fits properly in the ribbed grooves.
- Check with your hand to confirm that the belt has not slipped out of the groove on the bottom of the pulley.
- After installing a new belt, run the engine for about 5 minutes and recheck the belt tension.
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.
CHECK DISCHARGE 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 discharge warning light is lit.
4. Start the engine. Check that the light is lit.
If the light does not go off as specified, troubleshoot the discharge light circuit.
INSPECT CHARGING SYSTEM
VOLTAGE DROP TEST OF GENERATOR OUTPUT WIRE
This test determines whether or not the wiring between the generator "B" terminal and the battery (+) terminal is good by the voltage drop method.
PREPARATION
1. Turn the ignition switch to "OFF".
2. Disconnect the output wire from the generator "B" terminal. Connect the (+) lead wire of ammeter to the "B" terminal of generator and the (-) lead wire of ammeter to the output wire. Connect the (+) lead wire of voltmeter to the "B" terminal of generator and the (-) lead wire of voltmeter to the (+) terminal of battery.
TEST
1. Start the engine.
2. Turn on the headlamps and blower motor, and set the engine speed until the ammeter indicates 20A.
And then, read the voltmeter at this time.
RESULT
1. The voltmeter may indicate the standard value.
Standard value: 0.2V max
2. If the value of the voltmeter is higher than expected (above 0.2V max.), poor wiring is suspected. In this case check the wiring from the generator "B" terminal to the battery (+) terminal. Check for loose connections, color change due to an over-heated harness, etc. Correct them before testing again.
3. Upon completion of the test, set the engine speed at idle.
Turn off the headlamps, blower motor and the ignition switch.
OUTPUT CURRENT TEST
This test determines whether or not the generator gives an output current that is equivalent to the normal output.
PREPARATION
1. Prior to the test, check the following items and correct as necessary.
Check the battery installed in the vehicle to ensure that it is good condition. The battery checking method is described in the section "Battery".
The battery that is used to test the output current should be one that has been partially discharged. With a fully charged battery, the test may not be conducted correctly due to an insufficient load.
Check the tension of the generator drive belt. The belt tension check method is described in the section "Inspect drive belt".
2. Turn off the ignition switch.
3. Disconnect the battery ground cable.
4. Disconnect the generator output wire from the generator "B" terminal.
5. Connect a DC ammeter (0 to 150A) in series between the "B" terminal and the disconnected output wire. Be sure to connect the (-) lead wire of the ammeter to the disconnected output wire.
NOTE:
Tighten each connection securely, as a heavy current will flow. Do not rely on clips.
6. Connect a voltmeter (0 to 20V) between the "B" terminal and ground. Connect the (+) lead wire to the generator "B" terminal and (-) lead wire to a good ground.
7. Attach an engine tachometer and connect the battery ground cable.
8. Leave the engine hood open.
TEST
1. Check to see that the voltmeter reads as the same value as the battery voltage. If the voltmeter reads 0V, and the open circuit in the wire between generator "B" terminal and battery (+) terminal or poor grounding is suspected.
2. Start the engine and turn on the headlamps.
3. Set the headlamps to high beam and the heater blower switch to HIGH, quickly increase the engine speed to 2,500 rpm and read the maximum output current value indicated by the ammeter.
NOTE:
After the engine start up, the charging current quickly drops.
Therefore, the above operation must be done quickly to read the maximum current value correctly.
RESULT
1. The ammeter reading must be higher than the limit value. If it is lower but the generator output wire is in good condition, remove the generator from the vehicle and test it.
Limit value (90A alternator): 63A min.
NOTE:
- The nominal output current value is shown on the nameplate affixed to the generator body.
- The output current value changes with the electrical load and the temperature of the generator itself.
Therefore, the nominal output current may not be obtained. If such is the case, keep the headlamps on the cause discharge of the battery, or use the lights of another vehicle to increase the electrical load.
The nominal output current may not be obtained if the temperature of the generator itself or ambient temperature is too high.
In such a case, reduce the temperature before testing again.
2. Upon completion of the output current test, lower the engine speed to idle and turn off the ignition switch.
3. Disconnect the battery ground cable.
4. Remove the ammeter and voltmeter and the engine tachometer.
5. Connect the generator output wire to the generator "B" terminal.
6. Connect the battery ground cable.
REGULATED VOLTAGE TEST
The purpose of this test is to check that the electronic voltage regulator controls voltage correctly.
PREPARATION
1. Prior to the test, check the following items and correct if necessary.
Check that the battery installed on the vehicle is fully charged. The battery checking method is described in the section "Battery".
Check the generator drive belt tension. The belt tension check method is described in the section "Inspect drive belt".
2. Turn ignition switch to "OFF".
3. Disconnect the battery ground cable.
4. Connect a digital voltmeter between the "B" terminal of the generator and ground. Connect the (+) lead of the voltmeter to the "B" terminal of the generator. Connect the (-) lead to good ground or the battery (-) terminal.
5. Disconnect the generator output wire from the generator "B" terminal.
6. Connect a DC ammeter (0 to 150A) in series between the "B" terminal and the disconnected output wire.
Connect the (-) lead wire of the ammeter to the disconnected output wire.
7. Attach the engine tachometer and connect the battery ground cable.
TEST
1. Turn on the ignition switch and check to see that the voltmeter indicates the following value.
Voltage: Battery voltage
If it reads 0V, there is an open circuit in the wire between the generator "B" terminal and the battery and the battery (-) terminal.
2. Start the engine. Keep all lights and accessories off.
3. Run the engine at a speed of about 2,500 rpm and read the voltmeter when the generator output current drops to 10A or less
RESULT
1. If the voltmeter reading agrees with the value listed in the regulating voltage table below, the voltage regulator is functioning correctly. If the reading is other than the standard value, the voltage regulator or the generator is faulty.
REGULATING VOLTAGE TABLE
2. Upon completion of the test, reduce the engine speed to idle, and turn off the ignition switch.
3. Disconnect the battery ground cable.
4. Remove the voltmeter and ammeter and the engine tachometer.
5. Connect the alternator output wire to the generator "B" terminal.
6. Connect the battery ground cable.