This seems like the best place to post this. Please forgive me if this has been covered before. I've read several posts that have led me to testing a few things on my own, I just want to make sure I'm not missing something. Also, please forgive the long post, I just want to be descriptive and tell you everything I've seen, and what I've got going on.

Here goes:

I have a 1989 FXSTS Springer Softail. It sat up for a few months over the winter, and I thought I did the right thing by keeping it on a battery tender. About a month or so ago, I decided to crank it up and run it a little bit, just to keep things lubricated and moving around. I took it off the battery tender, and tried to start it. Being an older, carbureted bike, sometimes it's a bit grumpy and doesn't like to start if it's been sitting a while, but I've usually not had that much of a problem. I managed to get the motor to crank over a few times, and then it slowed and I got the dreaded clicking in the starter of a dead battery. It seemed odd, because it had been on the tender the whole time it was parked. I didn't have time to fool with it then, so I just left it until last week when I had some more time to figure it out.

I put it on a battery charger (as opposed to the battery tender) and fully charged the battery overnight. Once it was fully charged, I was showing a good 13.0v on the battery. It cranked up like it usually does when cold, meaning a little stubborn but no real trouble. I have a volt meter built into my gauge cluster (Dakota Digital, not stock H-D), and I was watching that. When it was cranking, voltage dropped down significantly, to around 9v or maybe just a little above. I've heard that under load while cranking it shouldn't go less than about 10v. When running, it seems the charging system is putting out a solid 13.5v at anything above idle, but at idle (around 700 rpm) it seems like it's just kind of running off the battery and not really producing anything from the charging system. I've heard a lot of motorcycles don't really charge at idle, so maybe that's not abnormal.

Anyway, so I rode it around a little bit, but when I parked it and went to start it later, it was only showing around 12v before cranking, and it really bogged down and dropped to around 8.5-9.0v while cranking, and I barely got it started. So I replaced the battery, figuring this one is just shot, because it seems like even though it charges up to a full charge (on the battery charger at least) it doesn't seem to have the capacity while loaded.

Here's what I've tested and found out. I did a continuity check across the two terminals of the stator, and it shows 0 ohms. I did a continuity check from each terminal to the engine casing to check for shorting, and it showed open for each, meaning it's not shorted. When running it shows about 25vac off the stator at 1,000 rpm, and about 45-50vac at around 3,000 rpm. Based on that, I think my stator checks out okay. As for the voltage regulator, as soon as I come off idle while riding around, it comes up to a solid 13.5v and maintains it, so it definitely doesn't look like voltage is going to high, which I think is a common problem with a bad voltage regulator.

However, I'm wondering if the voltage regulator output may be too low. It doesn't seem to charge at idle, and if you just let the bike sit idling at 700 rpm, you can watch the system voltage drop about 0.1v every 20-30 seconds, so it looks like it's only running off the battery at idle. When riding around, it's maintaining 13.5v, but I would have expected something closer to 14-14.5v to charge the battery and keep it maintained. Is my expectation for voltage too high? Is 13.5v while cruising normal, or is that low? Is it normal to not be charging and floating on the battery at idle?

I just want to make sure there's no other issue with the system. I would hate to have something screw up this new battery I just put in there. But since I've replaced the battery, and since the stator seems to check out and be making enough voltage, the only other thing left would be the voltage regulator. Everything looks clean and corrosion free, and all the connections are tight. Everything seems to be working okay now that I've replaced the battery, but I'm just not sure if the system voltage while cruising is too low, and I'm not sure if it's normal to not be charging at idle.

This is the first Evo Harley I've owned, so I don't have any experience with exactly what the voltage should be doing. I hope someone here on the forums can either tell me what I need to look for or if my voltage regulator may be bad, or if you guys can just put my mind at ease and tell me the voltages I'm getting are normal. Thanks a lot.

 

Take the battery to one of the Auto Parts stores and have them check it.

 

If the OP "checked the continuity across the two terminals of the stator and read 0", did he check it with one of the wires removed? If not, he got a feedback reading from the wiring, which did not afford a true continuity reading. So, in effect, he read a short which really wasn`t there. He needs to get a load test on the battery. And, as far as the battery not getting charged during engine idling, he`s probably not getting an accurate reading from his voltmeter under that condition. Most likely, the battery is getting a trickle charge as controlled by the voltage regulator, which is not being read by his voltmeter. My guess is that the original battery was no good, and that he needs to rely upon the load test. There is also the possibility that the charging system on this older bike won`t really charge the battery during idle, but that`s not really something to be concerned about since for normal operating conditions the bike will be run at a much higher rpm for longer periods that it ever will be for idling.

 

Get a new battery. The only way it could drop to a reading of 9V while cranking is if the battery were no good.

 

I'm the OP...Quick reply to everyone...

The battery has been replaced, because it was dropping so far under load. So that's a done deal.

As for the stator, continuity checks were done with the voltage regulator unplugged from the stator. I got 0 ohms (full continuity) between the two terminals, so it's got good continuity. I showed an open (infinite ohms, OL on the meter) when testing between each point and ground, so the stator is not shorted to ground, either. Maybe I didn't explain it right the first time, but that's what I got. Stator voltages with the bike running were also taken with the voltage regulator unplugged from the stator, and I got about 25vac at 1,000 rpm and about 55vac at 3,000 rpm. So as near as I can tell, the stator is good.

So, with the new battery, everything seems to start and run as it should. I'm just wondering if the system voltage may be a bit too low, and maybe some issue with the voltage regulator, at only 13.5v while cruising, and because it doesn't seem to charge at idle. It may be that the build in Dakota Digital gauge's voltage reading is not all that accurate, so I will hook up my voltmeter and see what voltage readings I get on it at idle and at cruising rpm.

I'm just wondering if 13.5v at cruising rpm is normal, or too low, and I am wondering if it is normal for the system to not really be putting anything out at idle. I had an old 1986 Honda VT700c back in the day that the owners manual even said it doesn't charge at idle, and to limit the time spent idling. I just don't know if I should expect the same thing from this 1989 Softail.



EDIT: Quick update. Since someone suggested the Dakota Digital volt meter on the bike may not be accurate (a fair assumption), I went to test everything with my volt meter. Truth be told, it's just a cheapy Radio Shack voltmeter, but still.

Anyway, so before cranking I got a solid 14vdc on the battery (it's been on the battery tender). When cranking, the lowest I saw the voltage go was about 10vdc, but that was on the Dakota Digital gauge's voltmeter. I didn't have an extra hand to keep the regular voltmeter attached while cranking. Anyway, while running, with the lights on like it would be when riding, the Dakota Digital voltmeter was showing about 13.5vdc at 1,000 and maybe a slight increase at any higher rpm than that. But the Radio Shack voltmeter showed around 14vdc, so it looks like the Dakota Digital gauge may be about a half a volt low. At idle, when the Dakota Digital gauge was showing around 12.5vdc, the Radio Shack gauge was still showing about 13vdc.

I'm thinking that everything may be good to go, and I'm just paranoid. I hate having to spend money on things like batteries, and I just wanted to make sure the system wouldn't screw up this new battery I installed. I definitely think my old battery was weak, and drawing down too low in voltage when starting, so it needed to be changed. But as near as I can tell, everything else seems to be working okay. I guess the Dakota Digital gauge is a good ballpark estimate for voltage, but it seems to read a little low, so that's probably my problem right there. I shouldn't have trusted that gauge. I'll keep an eye on things, but for now, I think my charging system is probably okay, unless someone has any other ideas. Thanks a lot, guys.

 

13V at idle isn't enough to keep the battery fully charged (needs at least 13.8V). At 2-3K rpms you should be reading 14-14.7 V. I think the voltage regulator is suspect.

I assume these voltage readings are directly across the battery, and all cables (pos. and grd.) are tight with no voltage drops.

 

I just replaced the battery two days ago, so yes, everything is connected tightly, with no corrosion present. The voltages I measured with my multimeter are directly across the battery terminals. The voltmeter built into my Dakota Digital gauge just measures the 12vdc gauge power supply (comes off the wire that used to light the gauge back light bulb in the old-style Harley mechanical gauge it replaced).

I noticed the Dakota Digital voltmeter reads about a half a volt lower than my Radio Shack meter connected across the battery terminals. I would tend to trust the Radio Shack multimeter a little more than the voltage indication on the gauge, so voltage is likely higher than the gauge indicates. Still...the Radio Shack multimeter is just a cheap pocket sized meter that cost me maybe $10-$15, so it's not the worlds greatest. I'm not sure how accurate it is, either.

I think, given the relative age of the bike I should probably just go ahead and replace the regulator. For the relatively small cost, it would bring peace of mind. I've only owned this bike for about 2 years now, and I know the previous owner replaced the stator a few years back. So it's got a relatively new alternator, a brand new battery, and if I replace the regulator, the whole charging system will have been replaced. Probably the best way to go.

 

I think that's a good plan. Output looks a little low and Voltage regulators don't cost a lot....so replace the 25 year old regulator and you should be good to go.

 

pyronuc, when you wrote your thread you did so immediately under a number of Stickies, two of which will help you check your charging system! Click on the blue "Electrical/Lighting/Alarm" above and read them. You will need a multimeter to check things properly, which will also enable you to check the accuracy of your voltmeter!

Also remove your new battery and charge it fully. Despite it being 'fully charged' it isn't, so give it a helping hand to help you!

 

Forgive me, but I've read up on testing the charging system, that's how I knew to test everything to get the results I posted even in the very first post of this thread. I know how to use a multimeter (Navy Nuclear Electronics Technician, here). I've posted my results I've found. My question was simply whether or not my system voltage is normal. It seems like it might be a little low, but is kind of in a gray area where maybe it is normal. I am not an expert on Evo charging systems, so I'm not sure if the regulator could be going bad or if my results are normal. That's all I asked.

And forgive me for saying so, I mean no disrespect, but if you're going to chastise me for posting without reading stickies, I should point out that I not only already mentioned charging the battery separately, but also that I have already replaced it. Based on that, I don't know why you would mention charging the battery when I've already covered that. Again, please forgive me, I'm not trying to be rude, but I just asked a simple question after doing all of the testing I have read up on.

Thanks though, seriously. I appreciate any help I can get, but I think I've got the battery situation sorted out, I'm just wondering if my voltage regulator is going out. And for the record, I did mention that I have decided to just replace the regulator anyway. Once I replace that, I will report back with the measurements I get with a new regulator.

Edit: I will go back and re-read the stickies in case I missed something the first time. Thanks for all the input, everyone.