Charging system help needed.

[Tsani]

Posted this on the EVO thread and thought I would post it here too. More exposure. Trying to help a friend get up and running.

"Need some help with a charging problem on a 98 Ultra. Not my bike, but a friends. He bought it a few months ago and it ran fine. Going down the road at night, threw the spots on and then battery slowly died. Battery takes and holds a charge. He went ahead and change the regulator before the rest of us OF's looked at it and fried the regulator cause when I read the stator out, it was grounded. So we changed out the stator (yep, you could see the burn in the stator coil), new reg and zip, nada. No charging. We are seeing 59 vac off the stator at 3000 rpms but the system is not charging. We are getting 11.75 vdc at the battery  no matter the rpm. Wiring to the regulator and from the regulator is new. Dealer techs tried two new regs with the same result, by which time Mouseman got fed up and rode or I should say, limped the bike home. They were just changing parts out with out finding the cause. Back at the garage, we jumped out the circuit breaker, in effect eliminating it, thinking there could be an issue there. Nope, 11.75 vdc. We also jumped from the ground point where the reg grounds right to the neg term of the battery with the same results. Could it be a rotor problem? Will a weak rotor give you a good volt reading? Any ideas? This is driving us nuts, Mouseman is going into shock cause he hasn't rode in two weeks. Help!"

As a side note, I have a 05 softail. My Manuals do not show my system the same as his. His, two wire from the stator to the reg, two out of the reg to the cb and ground. Mine has three wires from the stator to the reg and two from the reg one of which goes to the cb, then to the bat + term and the other wire to a local ground point at the regulator mount. Is his a single phase alt and mine a three? Just curious. Thanks for helping an old head out. I am used to generator pans and shovels. Still learning this new stuff.

[BikerJim44]

Howdy Brother Tsani, This is souning like there is a problem with the rotor. If the rotor and stator were mismatched that could cause a problem too. In other words if it's a 32 amp system and a 45 amp rotor was used by mistake or visa versa that would do it. I am not sure that the two would even fit but I suspect they do. Haven't run into a situation where that may have happened yet. LOL I'm sure it will one day though. Are you sure the new stator is good. There's nothing etched in stone that it was good out of the box just because it's new.
I'll tell you a story about the volt regulators. They are or were at least made by a company in Mass called Tympanium. I used to service their haz waste and got to know a couple of people there pretty well. The place was a piece work, sweat shop with lots of non english speaking asian women working in the assembly area. If the boss pissed them off they knew how to make the boards pass QA and would work for a short time then burn out. We as the end consumer were subject to that as most electrical parts are non-refundalbe but little did they know that I knew something about the inside of the operation. I know the company moved to a new more modern building and maybe work conditions have improved at least I hope but that is a possability that nothing has changed and they could still be doing this. Check all grounds too as well as maybe a bad ignition switch. Sounds weird but could be something to look at. Also check for shorts to ground. Spidey.

[Tsani]

Hey Jim. Thanks for answering. I will go over it myself. Trying to shoot this as a group just don't cut it. I would like to start at square one with it but some are getting antsy. I am fairly sure the stator is the right part unless the previous owner had upgraded the system which is doubtful but not impossible. Did they make a 45 amp set back then? BTW, can I check the output with the pos reg lead lifted and the neg lead grounded? Was thinking of isolating the system as much as possible but don't want to hurt anything.

[genedjr]

If you are getting 59vac off the stator, where are you measuring it?  Even though the harness is new, measure the input voltage at the regultor if its 59vac and the output directly off the regulator is 11.75vdc - the regulator is either bad - or not compatible with a 59vac input. 

Make sure when you test that you have the regulator output disconnected.  The bike will run off the battery, but if the regulator output is ok (13.5vdc+) disconnected and 11.75 connected, you have a harness or "other" problem sucking the juice.

...gene

[smoserx1]

I am not sure how a rotor could get weak.  Normally permanent magnets retain their strength.  I heard somewhere that the magnetism loss is something like 3% per hundred years, so I really doubt that is your problem, unless the rotor was to be degaussed, and that is unlikely.  The fact that the stator is putting out 59 vac at 3000 RPM, and that is also in the range of 16-20 volts per 1000 RPM it is supposed to deliver, indicates the stator is likely good.  And Harley does, in fact, use the same stator with different rotors (see service bulletin M-1111).  They use the same stator for the 38 and 45 amp systems on touring bikes, so I doubt a mismatch is the cause.  A mismatch can overheat a stator and shorten its life though.  Since you guys have essentially tried 3 regulators now and only get 11.75 V at the battery, I cannot help but think the 59 vac is not making it to the regulator.  You say the wiring is new.  On my bike there is no additional wiring other than that already attached to the stator and regulator from the factory that makes the components.  The only other wiring component is the socket connector where the two components plug together.   

And yes, your system is 3 phase if the stator has 3 wires.

[Tsani]

Thanks for the reply Gene. We measured the stator output right off the plug from the stator (unplugged from the regulator). aT 2000 RPM, it was 39-40 vac, then we brourght the r's up to 3k with 59 vac output. When we checked the regulator, it was wired into the system, so we will try that next. If that is good, then we have to find that vampire. I have been leaning that way all along but it is difficult to get a bunch of old knuckleheads to listen.   (I was it was a knucklehead I was workin on, them I know! )

Maybe a week before I get to this, But I will deffinately post what comes of it. Shared info is gold.

[Tsani]

Thanks Somersx1. Good to know something new about my bike. Never know when that will come in handy.

[genedjr]

Tsani - thanks
to what Smoserx1 said.

Let us know how you fair with the free advice.  We expect royalities!
...gene

[Zaps]

Check d ground wire at d regulator to frame.