Attention.
- Check that the battery wires are connected to the terminals.
- Never disconnect the wires from the battery while the engine is running.
Attention. Depending on the year of manufacture, different readings are possible.
Battery voltage measurement
1. If 20 minutes have not passed since the engine was stopped, turn on the ignition and turn on electrical appliances (headlights, blower motor, rear fog lights, etc.) for 60 seconds to remove the surface charge.
2. Turn off the ignition and turn off electrical appliances.
3. Measure the battery voltage between the negative and positive terminals of the battery.
Standard voltage: 12.5-12.9V at 20°C.
If the voltage is less than standard, charge the battery.
Checking battery terminals and fuses
1. Check that the terminals are properly attached or not oxidized.
2. Check the electrical conductivity of the fuses.
Accessory Drive Belt Check
Visually inspect the belt for excessive wear, damage, etc.
If any defects are found, replace the accessory drive belt.
Note. Cracks on the side of the belt ribs are acceptable. If the belt has missing pieces on the rib side, it must be replaced.
Discharge warning light circuit test
1. Warm up the engine and then turn it off.
2. Turn off all additional devices.
3. Turn on the ignition. Check that the discharge indicator light is on.
4. Start the engine. Check that the discharge indicator lamp is not lit.
Checking the voltage drop at the generator output connector
1. Turn off the ignition.
2. Disconnect the output wire from the terminal «IN» generator. Connect the positive lead of the ammeter to the terminal «IN» alternator and ammeter negative lead to output connector. Connect the positive lead of the voltmeter to the terminal «IN» alternator and the negative lead of the voltmeter to the positive terminal of the battery.
Test
1. Start the engine.
2. Turn on the headlights and fan motor and set the engine speed until the ammeter reads 20A. Then look at the voltmeter reading at this time.
Test results
1. The voltmeter can show the standard value. Standard value: 0.2 V max.
2. If the voltmeter value is higher than the standard (above 0.2 V), Possibly bad wires. In this case, check the wires from the terminal «IN» alternator to the positive terminal of the battery. Check for bad connections, discoloration due to overheating of wires, etc. Correct the deficiencies and test again.
3. After completing the test, set the engine to idle. Turn off headlights, blower motor and ignition switch.
Checking the output current
Preparation
1. Before testing, check the items below and adjust if necessary.
Check the battery installed in the vehicle.
The output current of the battery used should be equal to a slightly discharged battery. With a fully charged battery, the test cannot be performed correctly due to insufficient load.
Check alternator drive belt tension.
2. Turn off the ignition.
3. Disconnect the negative terminal from the battery.
4. Disconnect the generator output wire from the terminal «IN» generator.
5. Connect DC ammeter (0-150 A) in series between terminal «IN» and disconnected output wire. Connect the ammeter negative lead to the disconnected output lead.
Note. Tighten each connection securely as a strong current will flow.
6. Connect a voltmeter (0-20V) between terminal «IN» and mass. Connect positive wire to terminal «IN» alternator and negative wire to ground.
7. Attach an engine tachometer and connect the negative battery cable.
8. Leave the hood of the vehicle open.
Test
1. Check that the voltmeter shows the same value as the battery voltage. If the voltmeter shows 0V, then there is an open circuit in the wires between the terminal «IN» alternator and negative battery terminal or poor ground connection.
2. Start the engine and turn on the headlights.
3. Turn on the high beam headlights and the heater fan switch to the HIGH position, increase the engine speed to 2500 rpm and observe the maximum output current value shown by the ammeter.
Note. After starting the engine, the charging current will drop rapidly. Because of this, the action described above must be performed quickly in order to read the maximum current value correctly.
Result
1. Ammeter values must be higher than the limit value. If lower, but the generator output wire is good, then you need to remove the generator from the vehicle and check it. Limit value: 70% of rated current.
Note.
- The value of the rated output current is shown on the plate attached to the generator case.
- The value of the output current varies with the electrical load and the temperature of the generator.
- Therefore, the rated output current cannot be obtained. If this occurs, turn on your headlights or use another vehicle's light to increase the electrical load.
- The rated output current cannot be obtained if the generator or ambient temperature is too high.
- In this case, lower the temperature before testing.
2. After completing the output voltage test, reduce the engine speed to idle and turn off the ignition.
3. Disconnect the negative terminal from the battery.
4. Remove the ammeter, voltmeter and engine tachometer.
5. Connect the generator output wire to the terminal «IN» generator.
6. Connect the negative battery cable.
Voltage adjustment test
The purpose of this test is to test the voltage regulator.
Preparation
1. Before testing, check the items below and adjust if necessary.
Check the battery installed in the vehicle.
Check alternator drive belt tension.
2. Turn off the ignition.
3. Disconnect the negative terminal from the battery.
4. Connect a digital voltmeter between the terminal «IN» generator and the mass of the vehicle body. Connect the positive lead of the voltmeter to the terminal «IN» generator. Connect the negative wire to the vehicle body or to the negative battery terminal.
5. Disconnect the generator output wire from the terminal «IN» generator.
6. Connect DC ammeter (from 0 to 150 A) in series between terminal «IN» and disconnect the output wire. Connect the ammeter negative lead to the disconnected output lead.
7. Attach an engine tachometer and connect the negative battery cable.
Test
1. Turn on the ignition and check the battery voltage.
If the voltmeter shows 0 V, it means that the circuit is open between the terminal «IN» alternator and battery and negative battery terminal.
2. Start the engine. All appliances and lighting must be turned off.
3. Run the engine to 2500 rpm and read the voltmeter reading when the generator output voltage drops to 10 amps or less.
Result
Note. Below is a summary of the test results and may vary from model to model.
1. If the voltmeter readings match those listed in the adjustable voltage columns in the table below, then the voltage regulator is working properly. If the values differ from the standard values, the voltage regulator or alternator is defective.
Adjustable voltage table
2. After completing the test, reduce engine speed and turn off the ignition.
3. Disconnect the negative cable from the battery.
4. Remove the voltmeter, ammeter and engine tachometer.
5. Connect the generator output wire to the terminal «IN» generator.
6. Connect the negative cable to the battery.