Hello all. I’ve googled and searched the forums, but I can’t find any issues like mine. I have an 04 Ultra Classic that does not charge in idle even when I give her some throttle, but she charges going down the road as long as I’m above 2000 RPM. This is my first Harley. I’ve replaced the regulator and battery, and the stator seems to pass all the tests. Anyone have any ideas I can try?

 

How do you know it’s not charging, are you relying solely on the gauge?

 

I have my multimeter on the battery, and I get the check engine/battery light combo. I pull a P0562 in diag mode.

 

What tests were performed on the stator?

 

I tested continuity between the two wires, tested for grounding on each wire, and tested output.

 

On the off chance, when was the last time you cleaned the battery cable lugs, battery posts and chassis grounds. Over the years the corrosion on the connections will take a toll on power to the battery. Something else to think about, if you have the single phase(?) alternator the charge is only about 13.2V at idle. Using my 02 Dyna as an example, then above 2300 rpms it goes up to about 14.4v. Warm the bike up then test across the battery with a multimeter and check voltage at idle then at about 2400 rpms.

 

If all tested good and output was within specs, then I would still suspect the voltage regulator even though you said it was new. Is it an OEM or after market voltage regulator?

 

It’s a cycle electric. It’s only at idle and low rpm. I get the right voltage when cruising.

 

You say the stator is in spec but, out of curiosity, what are the stator out put voltages at idle, 2k and 3k rpm?
Also, when checking the cable ends for corrosion be sure th check under the insulation. Corrosion can creep up the wires and degrade their capacity.

 

At idle I got 25 V, at 2k about 40+ V, and at 3k about 60+ V. I do see previous owner oil cooler spills all over the area. Maybe oil has caused some current flow issues? I get great voltage while riding down the road as long as I stay above a certain throttle position. The reading coming from the gauge is what I'm looking at when cruising. Once I pull the clutch and the bike drops to idle the voltage goes with it.