Hi, Mathew in order to check out any circuits in the Charging System you have to start with a fully charged battery 12.5 volts or more and be able to pass a proper "LOAD" test if necessary, your battery may show 12.5 volts or more during an initial cursory test but in reality has little or zero amps and must be replaced. AGM batteries are prime for this type of deception. All voltage readings will be on the DC scale except for Stator Output which will be AC you will need a multi meter to conduct the following tests.
"WARNING" never plug or unplug any electrical connector in the charging system with the engine running !!!
1. Check battery terminals for damage or corrosion, check battery cables at "BOTH" ends for loose, corroded, or broken connectors, "INSIDE" and outside the cable harness, perform connector wiggle test and check cables with an ohmmeter if necessary.
2. Check the voltage drop at the battery when you hit the starter button, anything below 9.6 volts you might have a faulty battery.
3. Make sure your voltage regulator is properly grounded with a clean tight connection, then check voltage at the battery with the bike running between 2000-3600 RPM, depending on your system specs, your readings should be 14.3 to 14.7 volts. If you are not getting these numbers or the reading is 15 volts or higher replace the voltage regulator.
4. Faulty regulator diodes can allow excessive amounts of voltage going back to the battery causing it to overheat, boil its contents and swell the casing. The excessive voltage will also spike the charging system allowing light bulbs to surge brighter than normal until they fail along with the main circuit breaker.
5. Unplug the connector to the alternator and hook your multimeter leads to the alternator (pin/socket selection does not matter) set the multimeter to AC volts, at an idle the multimeter should read 16 to 20 volts AC. at 2,000 RPM 32 to 40 AC volts, 3,000 RPM 48 to 60 AC volts. If you are not getting these numbers, you may have a faulty alternator rotor.
6. Set the multimeter to OHM'S, connect one lead to the alternator (any pin/socket) and the other to a ground, the multimeter should read infinity. Connect both leads to the alternator multi meter should read 0.1 to 0.2 OHM'S. If you are not getting these numbers, you have a bad stator.
7. Check all wiring in the charging circuit for worn or chaffed spots and all wiring connectors in the circuit for corroded, broken, or loose pins/sockets, which is the # 1 offender.
For more information about your issue and valuable "FREE" downloads that you will need for viewing or printing please click on the blue links below and for more specific information or questions at no charge please feel free to contact me at [email protected]
Good luck and have a wonderful day.
Headlight dimming volt meter dropping Harley Davidson Forums
Harley Davidson Touring Workshop Service Repair Manual 2004
$10 very cheap includes a $60 electrical diagnostic manual
Instant Tech Relief
To speak to me personally absolutely "FREE"