Several precautions must be observed with alternator to avoid damaging the unit:
Noise from an alternator may be caused by a loose drive pulley, a loose belt, loose mounting bolts, worn or dirty bearings or worn internal parts. A high frequency whine that is heard at high engine speed or full alternator output is acceptable and should not be considered a sign of alternator failure.
See Figures 1, 2 and 3
There are several tests that can be done with inexpensive equipment. The first thing to do is to see if the discharge warning lamp on the dashboard illuminates when the ignition switch is turned ON . If it does not, check for blown fuses, a burned out bulb, or bad connections.
If the warning lamp does light with the ignition switch ON , but stays on with the engine running, check for the following:
If everything checks out OK, but the charge lamp is still on, the alternator itself is probably to blame. This does not mean the entire alternator needs to be replaced. Many times the voltage regulator may be faulty and cause a no charge condition. Check the alternator and regulator operation by performing the following tests.
If a battery/alternator tester is available, connect the tester to the charging circuit as per manufacturer's instructions.
Connect a voltmeter and ammeter to the charging circuit as follows:
- Disconnect the wire from terminal B of the alternator and connect it to the negative probe of the ammeter.
- Connect the test probe from the positive ( + ) terminal of the ammeter to terminal B of the alternator.
- Connect the positive ( + ) probe of the voltmeter to terminal B of the alternator.
- Ground the negative (-) probe of the voltmeter.
- With the engine running from idle to 2,000 rpm, check the reading on the ammeter and voltmeter. Note that the following readings are taken at an ambient temperature of 77° F (25°C). Voltage will decrease slightly as temperature increases.
- On models without the IC regulator, if the voltage reading is not within specifications, adjust or replace the regulator. The regulator can be adjusted by bending the regulator adjusting arm.
If the voltage reading is less than specified on models with the IC regulator, proceed as follows:
- With terminal F grounded, start the engine and check the voltage reading of terminal B.
- If the voltage is greater than specified, replace the IC regulator.
- If the voltage is less than specified, the alternator is probably at fault.
- Remove the ground from terminal F, if applicable.
To check the charging system under a load:
- With the engine running at 2,000 rpm, turn on the high beams and place the heater fan control switch on HI.
- Check the amperage reading on the ammeter. It should read 30 amps or more.
- If the reading is less than 30 amps, the alternator is faulty.
With the battery fully charged, the reading may sometimes be less than 30 amps.
REMOVAL & INSTALLATION
See Figures 4, 5, 6 and 7
- Disconnect the negative battery cable.
Failure to disconnect the battery can cause personal injury and damage to the car. If a tool is accidentally shorted at the alternator, it will become hot enough to cause a serious burn. On some models, the alternator is mounted very low on the engine. It may be necessary to remove the gravel shield and work from underneath the car in order to gain access to the alternator retaining bolts.
- Unplug the large connector from the alternator.
- Remove the nut(s) and the single wire(s) from the alternator.
- Loosen the adjusting lock bolt and pivot bolt. Remove the drive belt. It may be necessary to remove other belts for access.
- Remove the lower bolt first, support the alternator and remove the upper bolt. Remove the alternator from the car.
- Install the alternator onto the bracket. Leave the bolts finger-tight so that the belt may be adjusted to the correct tension.
- Adjust the drive belt tension.
- Connect the wires and plug the connector into the alternator. Make sure that the electrical plugs and connections are properly seated and secured.
- Connect the negative battery cable and check for proper alternator operation.