My 2002 FLHTCU is not charging at the moment. I followed the charging system diagnostics, and have ordered an new regulator.

I have several meters, all are 15+ years old. All different brands. None will show the ac voltage from the alternator. Testing a wall socket show 120vac on all three voltmeters.

What the heck and I doing incorrectly? I connect the volt meter to the alternator, both pin, and it shows 9-24 volts. 24 volts at about 3600 RPM. I thought it should show 24vac per 1000 RPM. I am not seeing the expected 80-100vac.

 

Seems like the voltmeters are telling you that the stator is kaput...

 

I'd agree, but 2 years ago I replaced the regulator and all was well. Same readings then as now. Will know when new regulator arrives.

Bought a better regulator this time.

 

That`s because the alternator has a built in circuit that changes A/C volts to D/C volts as well as dropping the voltage to a usable level to charge your battery. You can`t read the generated A/C voltage, only the output D/C voltage. You can read an A/C voltage drop to ground from the positive battery terminal, which will read very low (something like .3 volts) to indicate if your alternator is functioning properly. But this has nothing to do directly with the final D/C voltage output. In other words, there is nothing wrong with your meter.

 

 

 

If you're checking the voltage from the alternator to ground it won't work. You have to check from phase to phase. The windings are a delta configuration and don't have a ground reference.

 

Check each of the 3 wires from the stator separately between the wire and ground. Each of the three wires should have an AC voltage dependent upon RPM between about 10 and 30 volts AC. I don't recall exactly. Out of the regulator should be a pretty steady approximately 14 volts DC. These are with the engine running.

 

I have a stock 2002 alternator. I connected both meter leads to the two wire plug from the alternator. 2002 didnt use a three phase alternator.

 

I also performed the ground/short checks, and all those were as specified.