Measure
- 1. Check consists of power check and regulated voltage check, perform power check first • For simultaneous rating of electronic components, use suitable oscilloscope
- 2. The test can be carried out both in installed state and on bench. The test is described below for installed state; test on bench is performed analogously
- 3. A charged battery is necessary for test 1. Negative terminal from battery, alternator and regulator must correspond 2. Never allow alternator to run in an uncontrolled open circuit 3. Never short-circuit terminals to alternator and regulator 4. Never reverse polarity of alternator 5. For connection to an additional battery (e.g. starting aid) ensure that same battery terminals are connected to one another 6. When charging battery pay attention to polarity of connection terminals of charger • During charging operation in installed state, ground lead must be disconnected
Note. following safety measures:
- 4. Perform alternator power check as described in steps 6 to 21
- 5. Circuit Diagram 1. Load resistor connected in parallel to battery 2. Battery 3. Voltmeter 4. Ammeter 5. Ignition lock 6. Battery charge telltales 7. Alternator
- 6. Disconnect battery • Disconnect connecting cable from the alternator terminal "B+" • Connect ammeter (measuring range 100 A) into disconnect line
- 7. Connect adjustable load resistor to battery terminals • Set resistance before connection to "O" • First connect to battery, then to resistor • Connect rpm gauge • Connect oscilloscope in accordance with manufacturer's instructions • Connect battery
- 8. Start motor and read off generated current at different rpm
- 9. Adjust load resister, if required load currents are not attained
- 10. Shape of voltage curves on oscilloscope curve - shape should be regular
- 11. Test value - 5 to 7 A
- 12. If required minimum current intensity is not attained, or if oscilloscope picture shows variations, alternator should be overhauled
- 13. Circuit diagram 1. Battery 2. Ignition lock 3. Charge telltale 4. Resistor, for attainment of load current with battery set in series 5. Voltmeter 6. Ammeter 7. Alternator • Illustration shows typical alternator
Important. Only check alternator with parallel switching, charged battery. Switch off load resistor and battery after alternator standstill.
Important. Disconnection of load without parallel switching battery leads to voltage transients, which can lead to damage to diodes.
- 14. Connect tachometer, voltameter and load resistor according to manufacturer's instructions
- 15. Disconnect battery
- 16. Disconnect cable from alternator output terminal
- 17. Set ammeter (measuring range 100 A) between disconnected cable and alternator output terminal
- 18. Set resistor in series to battery
- 19. Start engine
- 20. Adjust load resistor, until ammeter shows prescribed value
- 21. Read off regulated voltage - ensure satisfactory