Good Morning, Saturday it finally warmed enough to ride in So. Il. So I took off and noticed the battery voltage was low. I had it on a battery tender, so I came back and began cleaning terminal and terminations. Found one relay corroded and cleaned it. All the while I was charging the battery. It took charge and held it good, so I took off again. Within 16 mi. Voltage dropped again and started getting idiot lights. Turned around and went home and began testing voltage at battery (10.3v) when running did not change. So I disconnected the stator lead from Voltage regulator. Checked for resistance. .003 ohms (good in my opinion) then checked for short to ground (none showed up with a craftsman meter). Then started it and checked the AC output from rotor @ 2500 rpm. (34v) I figured it was on the low side as it did not raise at all above that. I have read of one more test but have forgotten it. Does anyone else know it? (I'm not talking about taking to dealer for their testing)
Thanks
Jim

 

Did you go through the "Sticky" section of this forum concerning charging system testing? https://www.hdforums.com/forum/elect...sting-1-a.html
https://www.hdforums.com/forum/elect...sting-2-a.html

 

Thanks will look at stickies.
Jim

 

From your stator tests I'd say it's good. The output from the Voltage regulator is too low, should be 13.5 - 14.7 when running 2-3 K. Check where the Voltage reg cable terminates to see that they are tight and clean. You might also ohm out that cable. If all looks good, all battery cables,( both ends are tight and clean), I'd replace the Voltage reg.
Good Luck

 

I went through this same issue with my '01 FXD awhile back and my test results were exactly as you described here.

I cannot say for certain because I do not know how you performed your stator test, but I suspect there may be insulation breakdown of your stator coils creating an internal short and making a false load.

The coil resistance of .003 ohms seems too low, it should be higher, like 0.1 ohms or so, and the ac volts should fluctuate around 20 volts per 1K rpm. So a reading of 34 vac at 2500 rpm with the stator unloaded seems a bit too low, and if it does not fluctuate, then a bad stator is the most likely problem.

The voltage should fluctuate with engine rpm because there is no load on it. On my own tests, I have seen the ac volts output from an unloaded stator go over 50 vac at higher rpms. If yours will not go above 34 vac, then the stator most likely has an internal short within the coils caused by insulation breakdown and that is creating a false load. An internal coil short like this that is not shorted to ground would indicate continuity across the terminals like you read and infinity like it is supposed to and you will read some ac output, but it will go way low, maybe to zero, when you put a load on.

Because you report that the ac volts did not change above 34 vac, that is a red flag, and 0.003 ohms is another red flag. The voltage should fluctuate and you should read some resistance through the coil. Also, the voltage regulator and stator work as a system, a failure in one can signal a pending failure in the other. That is what happened to me.

Good luck and let us know how it goes.

 

Update!!!
I ordered a new stator from Ronnies, got it and changed it out. I started the bike and still low charge. So I changed the regulator and It's fixed. By the way I tried another regulator on the old stator and it would not charge then either. So believe skin man had it correct.
Thanks for the help.
Jim

 

Wouldn't you know it got it fixed and the weather has turned to YUCK! Salt on roads an inch thick. Oh well supposed to be nice weekend of the 20th
Thanks again appreciate all honest effort.
Jim