Hey all, I have a 91 sportster 883 that won't charge the battery. Should I change the voltage regulator first before I attempt stator/rotor? Stator and rotor seems like a much bigger job.

When I put a new, freshly charged battery in the bike, it is dead and will not take a charge within a week. I hope I am barking up the right tree with VR or stator/rotor. It also sat for a year when I was in Iraq, and it is gonna sit again for a year pretty soon. It started and ran fine after sitting, it seemed to stop charging part way through a 2000mi trip. Bike has maybe 30k miles on it. Hope this helps you help me figure this blasted thing out!

Also, can anyone recommend a seat that is comfortable for a long ride? Mine feels like I am sitting on a torture device after about 200 miles.

Semper Fi

Dan

Put a voltmeter across the battery terminals with the bike running. If it's showing less than 12 volts, then yes it's EITHER the regulator or the stator.

Thing is the only way to know for sure is to either test stator output OR IF there is a way to manually full-field the regulator do that. But I don't have specs for either on a solidmount.

Check the manual on how to test.

IF it was overcharging I'd say for sure it was the regulator.

But undercharging COULD be either.

K

K

Thanks a bunch. I'll take the first step by checking volts while running and see where that gets me. The manual calls for a load tester, which I am not sure what that is, or where to get it. Probably only used at shops and dealers, I imagine. Thanks again

Dan

K

Thanks a bunch. I'll take the first step by checking volts while running and see where that gets me. The manual calls for a load tester, which I am not sure what that is, or where to get it. Probably only used at shops and dealers, I imagine. Thanks again

Dan

A load tester (also know as a Carbon Pile tester) is designed to put a load on the battery, to draw the voltage down so that the regulator is forced to go full-field (full output).

IF under those circumstances the stator is STILL not making 14-15 volts, then the stator is bad.

IF under those circumstances output is good, but not when the load tester is not on, then the regulator (or the wiring it uses to sense battery voltage) is bad.

Anyway, your problem COULD be as simple as bad connections at the regulator. A ground wire off or loose or corroded terminal CAN be the cause.

Check the easy stuff first, then if you have to, let a dealer determine which it is.

Kev

Don't need it..

Pull the regulator cables at the stator...check both regulator leads to ground...if either is grounded, replace the regulator...

Resistance across the STATOR pins should be .2 to .4 ohms....

Check for ground on either regulator pin....

If either is grounded on either piece...replace it...

Another test of the stator is to run the bike at idle...there should be about 15-21 volts AC coming out of the stator...

Don't throw parts at it...buy the manual and TEST it.. :)

KevM Is right, but I would check all your wire connections, both ends, too for corrosion. It really doesn't take a lot of corrosion to have the same condition you discribed.
I say this because of the mentioned long term storage the bike was in.
Also put a fuel stablizer in your fuel the next time it goes in storage that will save you a lot of grief later too

Don't need it..

Pull the regulator cables at the stator...check both regulator leads to ground...if either is grounded, replace the regulator...

Resistance across the STATOR pins should be .2 to .4 ohms....

Check for ground on either regulator pin....

If either is grounded on either piece...replace it...

Another test of the stator is to run the bike at idle...there should be about 15-21 volts AC coming out of the stator...

Don't throw parts at it...buy the manual and TEST it.. :)


Good points, though I'll throw out that 0.2-0.4 ohms is a tough spec for cheaper meters.

I'll also point out that Ohm tests CAN prove a component bad, but they CANNOT PROVE A COMPONENT GOOD (in most cases).

Well if it is WELL out of range or IF it is shorted to ground YES it is bad.

However, shorts or opens can occur under heat/load that don't show up during a static ohm test.

So IF your readings are all good with static tests you STILL don't know for sure which component is bad.

K

Good points, though I'll throw out that 0.2-0.4 ohms is a tough spec for cheaper meters.

I'll also point out that Ohm tests CAN prove a component bad, but they CANNOT PROVE A COMPONENT GOOD (in most cases).

Well if it is WELL out of range or IF it is shorted to ground YES it is bad.

However, shorts or opens can occur under heat/load that don't show up during a static ohm test.

So IF your readings are all good with static tests you STILL don't know for sure which component is bad.

K

Agreed.....

heat related failures are the exception, not the norm, tho....

I just hate seeing people throwing parts at a problem...

Dan, you have a decent plan here now, and your work cut out for you...

Good Luck!

Yup, parts swapping is not the right way to do it!

Unless you happen to have in stock a slew of "known good parts"

But even then, a bad stator can fry a good regulator etc.

K

a load tester can be found at just about every tool store for about $20.00. I got mine at Harbor Freight on sale for $17.99.To Test the output of the stator, set your multimeter to AC and the range to 50-100 volts. The proper voltage should be 12-18 volts AC per 1000RPMS. For example at 1000rpm(idle) you should get 12-18 volts, 2000rpm 24-36volts. The regulator takes care of the supply to your battery and changes it to DC power. If you get the correct power from the stator, I would check the regulator and all wires dealing with the charging system. Sorry I went a little long but I have been there!!!!

You guys are all great. I do have a plan now thanks to you, and you explained things so even I can understand. I'd rather not throw parts at it . . .

I'll let you know how it goes.
Thanks again!

Dan

Now I am really confused. Okay, I started by buying and charging a new battery and hooking it up. I checked all wires from the regulator and checked the breakers (i think that's what they are) that sit on the rear fender. I cleaned all connections. I started the bike with a multimeter on the battery terminals. At first, I got 17.9 volts. after about 2-3 minutes of running, it dropped to 14.7v and stayed steady for the next few minutes, when I shut her down. the new battery was leaking out the drain like crazy. What do I do next? At least I learned how to use a multimeter! ( I think )

Thanks again for all your help!

Semper Fidelis

Dan

Voltage Regulator sounds bad. Did you do the test on the Regulator? Try unplugging the regulator and see if the battery still darins. If not, then you have something draining the battery and you are going to have to isolate what it is. Do you have any accessories hooked up to it or is all stock wiring? Check lighting for shorts, etc.

You can test for a drain pretty easily.Turn everything off. Disconnect the neg battery terminal. Connect a 12v. test light or your volt meter leads between the neg. cable and the battery. If the light comes on or if you have a volt/amp reading you have a drain. Pulling one fuse at a time will tell you what circuit is affected.The light will go out or meter reading will change. That will narrow down the search to only that circuit and you won't spend a lot of time checking good circuits. Good luck.

I started by buying and charging a new battery and hooking it up...At first, I got 17.9 volts. after about 2-3 minutes of running, it dropped to 14.7v and stayed steady for the next few minutes, when I shut her down. the new battery was leaking out the drain like crazy.
If I understand you to say you bought a conventional (non-sealed) battery, and after running the bike the battery is venting acid from the overflow tube, your battery is being overcharged. The voltage regulator's job is to maintain safe operating voltage range for charging your battery, and operating your 12v electrical components. Your regulator isn't working properly if it's delivering 17.9v across your batteries terminals. Your battery is being fried.

Yes sir, it is a new battery that I added the acid to. I assume that is a conventional non-sealed type. It has an overflow on the side. I have only had battery problems when it is running, not sitting, which leads me to rule out a drain. The only accessory I have is a plug for a widder electric vest, and all the turn signals and indicator lamp wires are taped off since they have all long since broke. Am I crazy to report 17.9v dropping to 14.7? There is still a chance that my novice use of a multimeter is to blame, but I held the terminals on the battery for the entire time. If my readings are good, is it still the regulator? No, I did not test the regulator yet because my lack of confidence with a meter yet.

Thanks again; we're gettin there!

Dan

The high voltage readings across your battery terminals, and the gassing-over of battery acid from the vent tube, indicate the battery is being overcharged. They are in concurrence. Your voltage regulator is faulty.

I second the overcharging, replace the regulator.

17.9 is too high, I'm not sure on a bike but in autos it is usually no higher than around 15.3v anything higher will cook your battery, burn out bulbs and possibly damage other electrical components. My guess would be a regulator also.
Sometimes, especially on a battery that you had to fill, you will get some acid cooking off at normal charge rates. This is usually from charging too fast or fluid level being too high.

OK HOLD ON A MINUTE!

You just bought ANOTHER battery?

Did you put it on a charger first before installing it and running it?

You're supposed to fill a new conventional lead/acide battery with the electrolyte, let it sit a specified amount of time, and charge it for a specified amount of time BEFORE installing it.

I don't know for sure, but IF you dump the acid in right away and throw it right into the bike, the regulator is going to go full field to try and charge the thing.

The fact that it dropped to 14.7 after a few minutes means the regulator WAS doing it's job.

Do you still have the old battery? If so, top it off, charge it, put it back in and run the bike and take a voltage reading. If the battery has a halfway decent charge and the regulator allows more than 15 volts indefinitely, then I'd say the regulator is bad.

BUT if the regulator holds the output between 12 and maybe high 14's then it's doing its job (sensing a need for a charge and charging it).

Take everything ONE STEP AT A TIME.

Kev

I got a new battery because the last one (which was a few months old) would no longer accept any charge at all. I followed the directions on the new battery by filling the supplied electrolyte, letting sit, charging for 10 hours, and letting sit again.

Oh yeah, I have been burning through headlamps like crazy for about a year now. I am beginning to suspect that this is related . . .

I have yet to test the stator as outlined, but hope to do that tonight.

Thanks

Dan

I got a new battery because the last one (which was a few months old) would no longer accept any charge at all. I followed the directions on the new battery by filling the supplied electrolyte, letting sit, charging for 10 hours, and letting sit again.

Oh yeah, I have been burning through headlamps like crazy for about a year now. I am beginning to suspect that this is related . . .

I have yet to test the stator as outlined, but hope to do that tonight.

Thanks

Dan


OK PHEW!

If that's the case and you still, even occassionally see voltage over 15 or so, then the regulator is bad.

Maybe it's an intermittent. Maybe something inside heats up and opens the control circuit or something, or maybe it just does it cold until it heats up etc. I dunno. But the job of the stator is to make power, the JOB of the regulator is to control it. If you have too much voltage it's the regulator (or the wiring for it).

Kev

The fact that it dropped to 14.7 after a few minutes means the regulator WAS doing its job.
Overcharging a good battery lowers its internal resistance. This, in turn, lowers the voltage across the battery terminals and increases the charging current (rate of charge). It's a viscous cycle of battery destruction. Your best bet is to replace your voltage regulator, Dan.

Okay, here is what I did, and the readings I got. Before I jump to the conclusion that the VR is bad, maybe I did something wrong?

Voltage when bike ignition is off, taken at battery terminals: 12.7
Voltage when bike is idling taken at battery terminals: 17.0
Unplug the two prong plug that I think connects the VR to the stator and put both voltmeter prongs in the female slots and I get 0.00 v. I switched them around to no effect, then put the red probe in one and black on a ground (engine mount) and then the other, but still got zero volts. This is where I am questioning myself.

What are your thoughts? Thanks again

Dan

Unplug the two prong plug that I think connects the VR to the stator and put both voltmeter prongs in the female slots and I get 0.00 v. I switched them around to no effect, then put the red probe in one and black on a ground (engine mount) and then the other, but still got zero volts. This is where I am questioning myself.

What are your thoughts? Thanks again

Dan

Output from the stator is measured with AC voltage....not DC...make sure you change the setting on the multimeter....

Checking for grounded parts is done with the bike OFF, and on the Ohm setting (resistance)

Chuck,

Boy, now I feel stoopid! But I guess that is the way to learn. Thanks a bunch for that info, I will try it here in another hour, this time with AC volts. For the resistance, I'll report the numbers, cuz I am still a little lost on that one.

Thanks again
Dan

Okay, the stator plug was measured (this time on AC volts!) and I got 24v at a high (choked) idle. I have no tach, so no rpms to tell you. This seems okay based on what you all said, so I think I am at the regulator as the culprit. Now, if I am not way off on this one, who do I buy one from? On-line or go to the dealer?

Thanks
Dan

Well, the one from the factory apparently failed. Why dont you give the aftermarket world a try? Cycle Electric makes excellent charging system componets for H-D's. Id try one of those before another stock one. They have a pretty good reputation.

Thanks, I'll get a new one and see if that works. You all have been great help, I'll let you know how it goes.

Dan

Good luck and happy trails, Dan. :)

Well, the one from the factory apparently failed. Why dont you give the aftermarket world a try? Cycle Electric makes excellent charging system componets for H-D's. Id try one of those before another stock one. They have a pretty good reputation.

Interestingly enough....Cycle Electric makes them for Drag Specialties...

Wouldn't be surprised if they had a HD contract at some point???

Very good products, regardless....

Well, the one from the factory apparently failed. Why dont you give the aftermarket world a try? Cycle Electric makes excellent charging system componets for H-D's. Id try one of those before another stock one. They have a pretty good reputation.

Yeah that factory one must be a piece of sh!t ............ it failed after only 17 years! :doh :frownthre

jason has a good point...but make sure you are reading ac volts not dc volts....the difference is huge.....

Dan S is taking a long time to get back with us. It's been over a year now wonder if he is still waiting for the votage regulator to get delivered...and if he is still reading this thread while he waits.....Bob