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Discussion Starter #1
hey all. so here is my problem. my bike is not charging. if i ride it around for a few days, the battery dies. i replaced the regulator rectifier a few weeks ago, but that didn't fully solve the problem.

i bought a tool that checks the battery and alternator. it's an idiot proof volt meter.
shop.oreillyauto.com/product_images/img/dor/84502.jpg

when i plugged it in to the battery with the bike off it read 12.0v (it says a normal battery). when i turned the bike on to test the charging system it read just under 13.0v (which it says is a "low output"). when i rev the engine, it goes up a little, but not to 13.5v (it says 13.5 is normal output).

i am trying to figure out what the problem is. i have 3 ideas (but really no clue).

1 - maybe the stator is shot? i wasn't sure about this because when i rev the engine the volt meter goes up. can a stator half work? can it put out a low output? i am hoping its not the stator cause that'll be a huge fix (or so i've read)

2 - maybe something else is sucking up more juice then it's supposed to? there are some other minot electrical problems. for example, i was having problems with the headlight until i replaced the fuse box. also, the neutral light is always on. i am thinking that maybe i have a bad connection somewhere.

3 - maybe the battery is shot. i had a friend jump the battery with a charger meant for a car and i was thinking that may have trashed the battery. is that possible?

any help you could give would be great. i have read a lot on these forums about how to fix stuff but i haven't been able to correctly diagnose the problem i am having.

i bough the bike used and i didn't know about all these problems when i bought it. it's been one thing after another. thanks all...
 

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when i plugged it in to the battery with the bike off it read 12.0v (it says a normal battery). when i turned the bike on to test the charging system it read just under 13.0v (which it says is a "low output"). when i rev the engine, it goes up a little, but not to 13.5v (it says 13.5 is normal output).
12.0V means practically drained battery. You should measure the charging voltage with a fully charged battery.

1 - maybe the stator is shot? i wasn't sure about this because when i rev the engine the volt meter goes up. can a stator half work? can it put out a low output? i am hoping its not the stator cause that'll be a huge fix (or so i've read)
Yes, the stator can partially fail so that it no longer produces the full output.

2 - maybe something else is sucking up more juice then it's supposed to? there are some other minot electrical problems. for example, i was having problems with the headlight until i replaced the fuse box. also, the neutral light is always on. i am thinking that maybe i have a bad connection somewhere.
Very unlikely. A full short would blow a fuse, and a partial short drawing enough current to exceed the charging system capacity would not go unnoticed. However, the regulator may have failed so that it constantly shorts one or more of the stator output legs. You can test this by 'rotating' the bullet connector connections from the stator (the yellow wires) so that each output phase is tried in each of the connections. Your headlight won't come on with all configurations if there are dead stator phases.


3 - maybe the battery is shot. i had a friend jump the battery with a charger meant for a car and i was thinking that may have trashed the battery. is that possible?
Possible but not likely. The charger can damage the battery only if the battery was initially empty, and even then the charging current diminishes to acceptable limits rather quickly. The cheap battery chargers with no voltage control will damage car batteries too if left connected for too long.


Charge the battery full with a charger. The voltage of a fully charged battery is about 12.6V. Let the battery sit disconnected at least half an hour before measuring. Then measure the charging voltage at battery terminals with engine running >= 3000rpm. Should be about 14V +-0.5V.
 

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Discussion Starter #3
thanks for the reply. very helpful. so i checked the voltage of the battery with the bike off at it read at about 12.5. when i turned the bike on at about 3500rpm, nothing really changed. i did it several times and got readings from 11 to 12.5 but never over 13 and nowhere near 14.

when i rev the engine, the voltage does rise, but not to the levels you said they should be at.

so it sounds like the stator is busted?
 

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1 - maybe the stator is shot? i wasn't sure about this because when i rev the engine the volt meter goes up. can a stator half work? can it put out a low output?...
Yup, I had the same problem with my stator...read the thread HERE
 

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Calif Rider
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Jon before you jump into replacing the stator make a good test on the regulator. Also clean up all your connections, stator connection, RR connections, fuse box connection also, if you have not done this yet. All these test can be found in the forum threads, just do a search for them. Hope it is something simple. Had sort of the same problems, part bad connections at stator and weak RR. A good solder job does better then the bullet connections for the wires from the stator to the RR. Check wires and see if they are heating up after running the bike, this is a good indicator of a bad connection. Had that problem with mine, it started to melt my connectors at the RR.
 

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I had an intermittent short in my stator. so yeah, it half failed. when I pulled it half of the coating on the wires were melted. replaced it and no probs since. but do as weh44att said and check all possible alternatives before doing the dreaded stator change. if you do have to do it, yes it is a pain but 250 bucks and 2 days I had mine going again and did it in an 8 x 10 metal shed.
 

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1985 VN-700
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I had a brand new battery that was bad. It had a shorted cell or something. Didnt matter NAPA had no way to check it so they just exchanged it. I used a hydrometer and checked each cell after charging for a day which showed dead cell. The only way to check a battery is to load test it and maybe only motorcycle shops have testers that can. Anyway, check for loose wires. The three leads from my stator were getting red hot, plus the white/red charging lead from the regulator. Also check the fuse to make sure its seated and is tight. I replaced the connections on my stator leads. I soldered them but it wasnt easy. I had a hard time getting the wire to take solder and an still not 100 percent satisfied that I got a good joint. But, I dont have the problem any more. The bad battery could have been putting excessive load on the system. I am an electrician by trade and for one thing, the fuse is a lot larger than the wires it protects, so the wire is the weak link.
 
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