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Premium Member
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Discussion Starter #1
At normal idle, engine just running, no choke, no throttle, voltage at battery is 14.7, (which is a little high right?)

But then as engine speed increases, that voltage reading at the battery starts to go down, like at 2500 RPM - 14.2 volts, and so on, then on shut off you can watch the standing battery drain from about 13.9 to 13.6/5.

Has anybody seen a reverse charge rate while running like that? Or have a thought what to look at next? R/R? Batt on the edge of dying maybe? Or the dreaded stator?

I've never seen the voltage reading drop as the engine speed went up. I imagine it's happened before, just not to me. (until now).
 

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Old Truck Junkie
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Mine does that with a new r/r. However; I am going to rewire my volt meter. I am getting my reading from the light circuit and I am going to rewire it directly from the bat.
 

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It's not reverse voltage, it's less voltage charging your battery so it appears to drop. Might be your r/r because at idle, volts are lower than 14. Test your batt w/o cables attached. Attach cables and check your batt volt. Turn on the key and check volts, Start your engine and check volts. What are your readings?

DT
 

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Sparky!!!
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Mine does that with a new r/r. However; I am going to rewire my volt meter. I am getting my reading from the light circuit and I am going to rewire it directly from the bat.
just use the accessory leads in the HL bucket, the are fused 30 amps, but get power directly from the battery.
 

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I had this issue, but I think it was because I swapped out the wrong blue wire to try to get the head light working. There are 2 plugs and I swapped the blue one on the wrong plug, when I swapped it back and swapped the other blue one everything was fine. now I am about 12.7 at idle and gets up to 14.7 at about 5k...

Could have been any number of things that caused it though, as I had had the bike apart a bunch, and swapping the the blue wires around the second time was after I finished the last reassembly, but before I even checked to see if it was charging. So if you swapped the blue wire, and your headlight still doesnt work, try it....
 

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Premium Member
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Discussion Starter #6
LOL, I know it's not backwards voltage, that's just how it struck me because it's charging the highest at idle, and the voltage goes down as the engine speed goes up.

I'm going out in a few for more thorough testing, I just wanted to toss it out and see if somebody has seen it before. I haven't moved the blue wire for my headlight, but I'll check everything.

I'm working with a monster kidney stone so it'll be slow going. Thanks for the replys, and I'll be back with results later. :smiley_th
 

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I'm working with a monster kidney stone so it'll be slow going. Thanks for the replys, and I'll be back with results later. :smiley_th
Gonna post pics of the stone? :drool:
 

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Linkmeister Supreme
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Put a cool Voltmeter on my 2002.
At first I wired it to the turnsignal wire in the headlight bucket as some have done on this site.
The voltage drop was almost 2 volts, so I connected it to the left ign coil and it works great.
I get 14+ volts at any rpm.
Once in a while, after riding quite a while and I have my lights on, I will see the voltage drop to 13 or so at low rpm, then it will come back up again with some higher rpm.
I just got this bike a while back and it looks like the stator has been replaced cause there are a few scratches on the engine cases.
When I re-set the air gap on the pick ups, I was happy to see that the stator looked like brand new......no signs of any heat damage.
I re-located the r/r and it looks original.
Should I worry about the slight voltage drop? It only happens for a few seconds.
BTW the PO just installed a new Yuasa battery but it's liquid type.:motorcycl
 

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Love My Baby
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You definitely should worry about the new battery. It's not maintenance free and it will be a pain in the you-know-what to keep it serviced properly. If you don't service it right, it very likely may leak battery acid all over the battery box and junction box etc.
 

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At normal idle, engine just running, no choke, no throttle, voltage at battery is 14.7, (which is a little high right?)......
I get this if my bike has sat for a few weeks, but only during the first few minutes after starting the engine (even with the choke off). I just assumed it was the charging system responding to the battery having sat idle for a while. It doesn't last long and after a few minutes or miles the charging system behaves normally (i.e., 13v at idle, fluctuating to 14+v with engine RPMs increases). No adverse effects, so it appears to be 'normal' for my '06.
 

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Premium Member
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Discussion Starter #13
Thanks Chris. I didn't spend alot of time checking to see if it changed, but thats something I can look into now.
 

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I read the post and said "Somebody else gave almost that exact reply earlier." So I looked and saw it WAS the exact same post dirtrack had made. Then I saw the link to handbags and watches. Duh!
 
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