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Discussion Starter · #1 ·
Hello again, I've been gone for while. I removed the plastic connection on the stator wires and "hard wired" them back together with spade connections, I tested the wiring with a meter (set on ohms) and got good readings. I checked for battery drain between starter relay (solenoid), set the meter to amps and plugged the red lead into the 10A fused outlet on the meter and touched off negative post and negative cable, same thing with for MA. I plugged the red lead back into the voltage outlet I checked for volts same way, .000 readings both times. When I checked between the battery negative post and ground cable I get 12.43v, seems to me that qualifies as a direct short somewhere. No blown fuses no melted wires that I can see. With a meter I get 13.3v at idle and 14.5 at cruising rpm, anybody got any ideas as to why I would have voltage on negative battery post?
 

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... voltage on negative battery post?
That could happen if you were connecting it to alternating current instead of direct current.

Try an oscilloscope ... oh wait, none of you guys have those. Rent or borrow an oscilloscope if you really want to see what's happening, they work great on your :unsure: what is it you ride again?
 

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2003 1100cc classic V-Star :sneaky: after extensive research I found it.

lol it has a fuel pump too.
 

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Discussion Starter · #4 ·
2003 1100cc classic V-Star :sneaky: after extensive research I found it.

lol it has a fuel pump too.
Sorry about the rookie mistake! Always nice to know what bike I'm talking about. Ahh no, I did have the meter set on up to 20v dc, and your right, I don't have oscilloscope. Yes the bike does have a fuel pump and this means...? I did notice when the positive side of the battery is connected I would get the 12.43v reading, when I pulled the positive cable off, the 12.43v reading would disappear. I'm checking between the negative battery post and ground cable and getting this kind of reading.
 

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I was looking for a service manual for your bike, but so far have not found one. That really is the best way to start, the reference to the bike having a fuel pump relates to another thread. The service manual will give you the correct test procedure for your bike and they usually start at the alternator outputs. Regulator and rectifier is tested on the quality of the regulated DC output and the battery is what it sounds like you are testing to get a steady reading of 12.43vdc

Is it a digital volt meter that displays negative DC voltage if you reverse your test probes?
... so easy with an oscilloscope what you see is what you get.
 

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I'm having a hard time understanding exactly what your question is...
Could you re-ask it in simple?

S F
 

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Discussion Starter · #8 ·
@slick nick, thanks for the formation. @Trials, yes it is a digital volt meter, no I did not try reversing test probes, not something I would do consciously, checking negative side of relay (solenoid) or battery with black probe and red probe to ground cable, not sure that would make any difference. Did I check by placing black probe to positive side and red probe to negative side on battery or solenoid? No. Getting a negative DC voltage reading proves what? That the meter is working properly? I'm no electrician so bare with, ok?
 

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Discussion Starter · #9 ·
@easyrider, are you out there? I get the latest discussions in my email, I've tried to reply to you about your response that I experiencing an open circuit. Ground cable needs to be pulled and cleaned, put back on and tighten but not to tight. Apparently this forum is different than the one I receive in the email, not sure if this is going to reach you or not. Thanks for the information about cleaning up the ground cables. I'll have to ask the head honchos at motorcycle forum and see if I get on the same page.
 

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I guess people have forgotten that a meter reads a/c too, who needs an oscilloscope? If you kept the old needle analog meter like I did they clearly show negative voltage too.
 

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Try an oscilloscope ... oh wait, none of you guys have those.

I do I do I do!! :)

I also have a bad ass Snap on Battery analyzer with a scope built in.. I love when shops close and sell thier equipment..lol

anybody got any ideas as to why I would have voltage on negative battery post?
Your either testing an AC circuit, or the method your using is not "giving" you a posative signal, but is a completion of a circuit that already has a posative.
Dc systems need a power and a ground to operate, you are already connected to a power source, and the ground is completing the circuit. basic example is a simple test light to both battery connections. it wont light up without one or the other.
 

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Discussion Starter · #12 ·
@amc49 I do have an "old analog needle meter". With the battery on the bike, positive side still connected, I took the negative cable off the battery and put the meter probes between the negative post on the battery and the ground cable and got a +12.43 reading on the meter. I received a reply from a member easyrider who is a master electrician and says this condition means I have an open circuit (the ground is not making a good enough contact). He says I need to remove the ground cable and clean it off and put it back on making sure it's down tight. I know he's talking about the ground connection to frame and motor. There's the rub, the factory put those connections on what looks like frame between the lower backend of the motor and the frame. It looks like I'm going to have to approach from the bottom of the bike with a box end wrench, maybe.
 

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Don't want to slam your master mech but what you just described is what we in the car world do to test for circuits powered up to run battery down when key is off and car sits like overnight. You getting power is no open, it is evidence something is still powered up somewhere if key is off. On a car we start by yanking fuses one at a time and when the power suddenly disappears you then look at what that fuse powered up to narrow down finding your errant power not turning off. First thing you do is disconnect alternator/regulator as they bleed power all the time if diodes are not loaded enough to block power.And on a car one needs to know the amount of power always on when the computer is asleep and awake, those numbers can be confusing.

Your mech may have been sarcastic as when you take the ground cable off battery you yourself have produced an open circuit, you opened it at the grounding point. The 12.43 volt does not come into that at all, another issue.

If your grounding includes a strap to frame you can test anywhere on frame you want as long as clean metal is there and it is the main frame. I do 90% of my ground testing nowhere near a battery.
 

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Alternating Current (AC) flows one way, then the other way, continually reversing direction between negative and positive output. How could you get negative voltage readings at the positive terminal of the battery? <- Easy, you fail to rectify the voltage from the alternator and now your meter is seeing both negative and positive voltage output.



... well actually you would see the sine wave if you had an oscilloscope, but with a simple volt meter you are not going to see anything but changing numbers and voltage output by average.

What happens when you reverse the test probes on a digital multimeter that is capable of displaying negative voltage readings? Easy, the voltage reading will be preceded by a minus sign on the digital display.


Is your ground connection solid or does it have resistance? <- You can meter test that with the continuity setting on your multi-meter, just make sure you set it to a high enough sensitivity setting that it can read a very small amount of resistance in the grounding wires. ... in other words you could determine if your ground cable needs to be removed and cleaned and reconnected with nothing more then a simple meter test.
 

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Discussion Starter · #15 ·
Thanks Guys for all your help, @amc49, Feeling a little foolish after hearing your explanation of why I would be getting an "OPEN" circuit. I'm not an electrician, I thought I shouldn't since I was making contact with the meter, sounded good at the time. As for the rest of you guys, I know I can use the information when the stator goes out. As I understand it, the stator puts out AC to the regulator/ rectifier and that converts it to DC back to the battery and runs everything else. An OEM stator is expensive! man I hope that doesn't burn up! Thanks again. When on the road, keep your eyes out and stay safe.
 
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