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Old 06-16-2008, 11:03 AM   #11
Easy Rider
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Originally Posted by sportpsyc
until I find which ground wire has a short. BTW everyone--should I do this by measuring resistance, or would it be better to do with the key on and the system hot?
Technically, you probably are looking for a ground (wire) that is OPEN, not shorted......probably.

Hard to give a good answer to the second part. Resistance readings CAN be decieving......because of the aforementioned secondary or back-door grounds.
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Old 06-16-2008, 02:15 PM   #12
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Change the name of your bike to Christine, LOL
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Old 06-16-2008, 03:55 PM   #13
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Man, at this point, I would LOVE it if this thing was like Christine--at least Christine fixed herself when she was broken! :-) I don't mind if she runs over a few people and catches on fire, as long as she'll self-repair...



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Old 06-17-2008, 12:06 AM   #14
5th_bike
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Originally Posted by sportpsyc
Okay..here's the latest...hope your brain(s) aren't tired...
On to the relay: I first tried replacing the actual snap-in relay. No difference. I then put my multimeter on pins A (the entry point to the relay) and C (the other side of the diode), and got .7V, .....
OK so the relay(s) is/are good. I meant, the relay 'as is' - not plugged in.
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.... Here's the freaky thing. With the proper side stand switch plugged in, everything is dead--all lights, horn, everything. Dead......
Freaky indeed (see below at 1)
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The moment I plug in the side-stand over-ride plug, everything works PERFECTLY. .....
No wonder, when it's in neutral, it doesn't really matter what position the side stand switch or any substitute is in.
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Originally Posted by sportpsyc
Until, of course, you put it in gear, at which point it all still works, but the blinkers blink fast. .....
Maybe *that's* why there is a diode in the side stand switch, the blink frequency could be dependent on the actual 'ground' voltage of the blinker circuitry, normally, 0.6V-0.7V, but with the 'override plug', 0V).
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Originally Posted by sportpsyc
... Of course, after reading the wiring diagram, the relay would have to be working properly, because the neutral indicator light is working properly in ALL conditions, which means the relay would have to be working correctly since the neutral light is the first thing AFTER the relay, and is on it's own circuit. SO, after that, we start looking at where the neutral light grounds too. .....
That is not totally correct - the neutral indicator light has its own circuit yes, from +12V (fuse nr. 4, orange/green wire) to the light, to the side stand relay pin B, to a diode to pin A, and to the neutral switch, to ground. The neutral switch also provides a ground to the side stand relay, which enables you to start and run the bike with the side stand down, if it is in neutral. You should consider the neutral switch as 1) a light switch 2) an 'override' for the side stand switch. The neutral light is not the 'first thing after the relay'. The neutral switch and the side stand switch are the two 'first things after the relay'.
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And thats where things get messy, because there are so many things commony grounded. Okay. Anybody see any flaws with my logic so far? I pulled the headlight out, and I don't see anything obvious. This whole crazy nonesense of things working "better" with the override plug in has really got me baffled. I am up for round two of suggestions! :-) .....
Well 1) I would disconnect and then diode test the 'new' factory side stand switch (pushed 'in') for 0.6 V in one direction and 'no connection' in the other direciton.
Also 2) I would replace the "twisted together five years ago" wires with a solder connection, or if you don't like soldering, try to make a 'fresh' twist (cut old wire ends off, strip a little plastic, and twist together again, with a wire cap. Or, maybe better:
3) try to replace the twisted connection with a diode (normal silicon diode, Radio Shack you know, they're not expensive. To make it fail safe get 2 diodes and put them in parallel, but with opposing direction. Then, it doesn't matter which way you connect them, and you will always have 0.6 V over them. The signal lights may just start blinking normally (this is a wild guess....).
Quote:
Originally Posted by sportpsyc
Thanks everybody--I can't tell you how much I appreciate the advice and support with this one....
Well first try and get it running please...
Apart from checking the entire ground circuit thoroughly, as Easy suggested, I would not know where else to look... We're running out of parts to consider...

Voltage does not say much. It shows that there is a connection, but not how good it is. Resistance measurements are a little better, so undo the positive battery wire and get the ohmmeter out. Measure between negative battery pole and every possible ground connector. As I said before, when testing the 'ground' wire that goes via the [side stand switch or the] 'override plug', put the bike in gear. When you measure, do 'wiggle' the wires a bit to see if the reading fluctuates.
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Old 06-17-2008, 02:10 AM   #15
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Will do--I have a soldiering iron, so I will give that a go just to be sure. I actually did re-twist the override plug wires, but it might lower the resistance a bit is I go ahead and soldier it.
To double check, to test the diode, I need to set my DMM on Volts, and put a lead on each end of the diode circuit, and then switch the leads, correct? One way should give me a reading and the other way should not (or at least a much lower reading), correct?

So to re-state your instruction for clarity, I take the pos. battery cable off, and put the negative DMM lead on the negative battery post (or on the frame for that matter since the neg. battery terminal just grounds to the frame anyway...), and the pos. DMM lead to every ground wire I can find in the system starting with the grounds closest to the battery. The first place where I get either an OL reading or 0.0ohm resistance back to the battery will give me the segment that has the problem. And resistance should increase the further I get from the other lead, I think. One thing I am not is and Electrical Engineer, so does this sound right?

5th Bike, and Easy Rider, thanks for all the time you guys have spent typing and thinking about this. I really do appreciate it.



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Old 06-17-2008, 10:02 AM   #16
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No, your DMM should have a special 'diode check' mode, with mine it is a 'sub'mode of the ohms measurement, a little diode symbol appears in the display, and its readout is in volts.

When you measure resistance, anything close to 0 ohms is good. As far as I know, the requirement for a house's ground wiring is that the resistance to ground should be less than 2.5 ohms. OL means that there is no connection, and indicates a problem. Do make sure you make good contact, little layers of oxidation on metal often make it seem that you have no connection. Carefully poke the sharp point of the DMM lead into the metal, then you should be OK.

(Edit: about 4 spelling errors, and: to at least try to avoid the 'false ground' problem that Easy mentions below, try to unplug as many connectors as possible, and connect only those needed to complete the path to the negative battery pole. Do start with the green wire from the side stand relay pin C (unplug first)) Good luck.
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Old 06-17-2008, 10:36 AM   #17
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Originally Posted by sportpsyc
So to re-state your instruction for clarity, I take the pos. battery cable off, and put the negative DMM lead on the negative battery post (or on the frame for that matter since the neg. battery terminal just grounds to the frame anyway...),
Both for testing a diode AND tracing a ground, the meter should be set of OHMS, not volts.......but the positive side of the battery MUST be disconnected or you will let the smoke out of your meter !!!


If you are going to try to trace grounds with the ohm-meter, put one lead on the (-) battery post or the cable that connects there. DO NOT connect it to the frame. We are, after all, maybe looking for something that is connected to the frame but NOT to the negative battery.

And I've got to mention again (appologies to 5th) that trying to trace the grounds with a ohm-meter may not be the best way......because of secondary, back-door grounds. If you DO that, be suspicious of any reading above 0 ohms. Calibrate the meter by shorting the leads together to be sure a dead short actualy reads 0.

As long as we are doing this, maybe I should define: secondary, back-door ground. :roll:
It is a path to ground through another branch of a circuit or through another device when the physical ground is absent.
If, for instance, there are several things in close physical proximity that all need a ground, it is common to tie them all together and the run a heavier wire to the frame ground. If that common wire goes open, the negative side of the devices are still tied together. Sometimes one, or more, of those devices actually supplies a partial path to ground........so that a tiny bit of current still flows.....and an ohm-meter will still give a reading........although not enough current to make things work right and the meter will not read a "good" zero.

Whew. Sure hope "we" get this fixed soon. All this worry and effort is tiring me out !!!! :lol:
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Old 06-18-2008, 01:58 AM   #18
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Whew. Sure hope "we" get this fixed soon. All this worry and effort is tiring me out !!!!
I agree! Please, let me buy you both a virtual beer. It's nice and cold. :drool:

This weekend I am gogin to take the bike completely apart so I can get to everything, and spend the day in hell trying out all your good suggestions. How about if I get my web cam, and a long USB cable, and we can get on Skype and you guys can take turns telling me what the hell to do, and making fun as look like a monkey having sexual relations with a football and sounding like an adult version of Yosemite Sam. Sounds like a good Saturday, right?

To clarify one last thing, the longer a wire, the more resistance it has, and the higher Ohms, right? So it seems to me that if you have an Open Line (OL) early in the system, then it will either read OL or it will show a very low resistance. Another way to say it is if I am measuring ohms in a 10' wire, and I get no resistance, then something is likely WRONG, correct? Who'd of thunk that you'd be given DMM lessons on the GZ250 page. We have now elevated this forum to a WHOLE other dimension...do I get a free status upgrade from "Newbie" to "Official Pain in the Ass"?
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Old 06-18-2008, 07:33 AM   #19
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Copper wire has very low resistance. For example, ten feet of 18 gauge wire would have a resistance of 0.0751 ohms. If you have a wire on your bike that has any significant resistance. Depending on the meter you have it might not be able to accurately read resistance this low.

Wire Gauge Resistance per foot

4 .000292
6 .000465
8 .000739
10 .00118
12 .00187
14 .00297
16 .00473
18 .00751
20 .0119
22 .0190
24 .0302
26 .0480
28 .0764
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Old 06-18-2008, 10:36 AM   #20
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So it seems to me that if you have an Open Line (OL) early in the system, then it will either read OL or it will show a very low resistance. Another way to say it is if I am measuring ohms in a 10' wire, and I get no resistance, then something is likely WRONG, correct?
Terminology is important. Like Bob said, unless you have a REALLY good meter, the resistance of the wire itself is probably not a factor in the actual readings. No resistance (open) is different than zero resistance (short). On the old meters, measuring a wire would give a 0.0 reading and measuring the open air would give you an infinity reading; I assume that is what you are referring to as OL.

So, when measuring something that should be connected together with a wire (or equivalent), you should expect to see 0.0 ohms (or maybe 0.1). Anything higher than that and there may be a problem. (The first "problem" being that the meter leads are not making good connection!)

I'm not really fond of digital meters. I still like to see that needle move.
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