Alternator Performance Testing
- If battery is overcharged go to BENCH TESTING . If battery is undercharged, check alternator wiring harness connections and drive belt tension. Ensure battery is fully charged. Connect a voltmeter to alternator "B" terminal and ground. Connect ammeter positive lead to alternator "B" terminal. Connect ammeter negative lead to positive side of battery and start engine.
- With all accessories off, increase engine speed from idle to 2000 RPM and read meters. Voltmeter reading should be 14.4-15.0 volts at 68°F (20°C). Voltage reading will vary depending on regulator case temperature. Ammeter should read about 10 amps. Turn engine off.
- If voltage is higher than standard value, check brush ground. See BENCH TESTING . If brush ground is okay, replace IC regulator.
- Load test with engine running at 2000 RPM and headlights and heater blower motor on. If current is less than 20 amps, go to BENCH TESTING .