GxT V044-01, Ferret 44 Battery Tester with Printer Manual - Manual (Page 10)

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Alternator Output Test (Manual)
Al ways compare test results with manufacturerʼs specifi cations before coming to conclusions regarding the
performance or effi ciency of charg ing systems and their components.
1. Be sure the Load Knob is turned to OFF before
connecting the analyzer cables to the battery. Take
note of the safety pre cau tions on the back cover of
this manual.
2. Connect the analyzer Battery Clamps to the battery
terminals; Red to positive, Black to neg a tive.
3. With the Amp Probe jaws closed and not around any
wires, press the Zero Amps but tons until the Amps
Display shows “000”
4. Place the Amp Probe around the al ter na tor output
wire. Try to po si tion the probe away from strong
magnetism near the back shaft end of the al ter na tor
to avoid mea sure ment error.
5. Press the Amps/Volts button
6. Start and run the engine at about 2000 RPM.
7. Turn the Load ON and increase until the battery voltage
decreases to be between 12 and 13 volts while reading the output amperage.
8. Turn Load OFF and reduce RPM.
9. Test Conclusions
If the Amps Ripple lamp stayed on during the output test replace the al ter na tor.
If the amperage abruptly decreased during the test check for a loose belt.
If output was less than 90% of rating use the voltage drop test to check output resistance.
If output did not change, full fi eld the alternator. If the alternator output increases, replace the regulator.
Regulator Charging Voltage Test
Follow the same setup and test procedure used for the alternator test, except put the Amp Probe around either
battery cable. Once the charging amperage drops below 20 amps, the voltage displayed will be the regulator
setting. This should be between 13.5 and 15.5 volts on a 12 volt system.