- a) Check the condition and tension of the accessory belt. If it is worn or damaged, replace it (see chapter 1).
- b) Make sure that the generator mounting bolts and nuts are tightened.
- c) Inspect the generator wiring and electrical connections. They must be in good condition and securely tightened.
- d) Check the large fuses in the engine compartment (Chapter 12). If any are blown, determine the cause, repair the circuit, and replace the fuse. (If a fuse is blown, the engine will not start and/or the accessories will not operate.).
- d) Start the engine and check for any unusual noises from the generator that may indicate wear of its bearings or brushes.
- e) Make sure the battery is fully charged.
- g) Disconnect the battery cables (negative first, then positive). Inspect the battery terminals and cable terminals for corrosion. Clean them if necessary (paragraph 3 and Chapter 1). Connect the wire to the negative terminal.
- h) With the ignition off and all auxiliary units switched off, connect the test lamp to the negative terminal of the battery and the disconnected negative terminal of the wire.
If the test light does not come on, reconnect the terminal and proceed to the next procedure.
If the indicator light comes on, there is a short circuit in the electrical system. This short circuit must be repaired before the charging system can be tested.
To detect a short circuit, disconnect the generator wiring:
- a) If the indicator light goes out, the generator is faulty.
- b) If the light continues to glow, remove the fuses one by one until it goes out. This will help identify the component that has shorted.
2. Use a voltmeter to measure the battery voltage with the engine off. It should be around 12 V.
3. Start the engine and check the battery voltage again. Increase the engine speed until the voltmeter reading stabilizes. This should be between 13.5 and 14.6 V.
4. Turn on as many electrical consumers as possible (headlights, rear window heater and heater blower) and make sure that the alternator maintains a regulated voltage of 13-14 V. The voltage may drop and then increase again. You may find that you need to increase the engine speed slightly, even if the charging system is working properly.
5. If the voltage reading is higher than specified, replace the voltage regulator (paragraph 13).
6. If the reading is less than the specified value, the fault may be due to worn brushes, weakened brush springs, faulty voltage regulator, faulty diode, worn or damaged collector rings, or a break in the winding. The brushes and contact rings can be checked (paragraph 13), but if the fault persists, the alternator should be replaced or sent to an auto electrician for inspection and repair.