CRAZY voltmeter to ground readings - whatthe?

[Speedo]

Instead of the meter being steady in its readings, it looks like it is "going crazy" with readings you can't read because they are fluctuating so much. I will say that after the RR was totally toast, the reading did not jump around any more, readings were just too high - the voltage simply get going up proportionally to rpm, past 17v. In other words: voltage was NOT being "regulated" since the RR died.

Shiraz's bike, when we tested it, showed virtually no movement on the RR voltage readings when we reved it to whatever. It was rock solid at 14.5v or so as we reved to various rpm. I mean rock solid....no up, down, wild searching for a reading....just right on with 14.5 no matter what we did with throttle.

But other tests in Stator Papers apply and were "funky" as well as some tests Shiraz knew to do but NOT in Stator Papers; specifically, with everything hooked up correctly (rr, stator, etc), on my bike there is some kind of "rogue" voltage that shows up on both of our meters just by attaching either lead to any ground on the engine or frame. Crazy stuff, should be 0/Zed/nada/nothing. I'll test again after new RR arrives.

Here is the remaining mystery to date in my ordeal:
1. RR rewired direct to battery positive and to battery negative; stator rewired direct to RR. Improved readings (last post, no longer important), then RR died.

2. ShirazDrum noticed CRAZY constantly fluctuating readings from voltmeter with only the ground connected (positive on nothing or anything, doesn't make a difference). Both of meters did exactly the same thing.

3. Ordered and installed new RR. Same thing as far as ground CRAZY readings. Only difference is that when measuring across battery, voltage reading no longer increase in linear fashion with rpm and "peak" (still w/ crazy fluctuation) at about 15v.

What I observed:
a) Ignition ON or OFF, Bike NOT running, across battery is steady 12.5ishv or so (i.e. normal).

b) Bike RUNNING, connect voltmeter lead to ANY ground, even the battery itself, makes no difference, there is this CRAZY fluctuation of readings.
* disconnecting any or all three stator wires makes NO difference at all.
* visual inspection of stator wires (with clutch & front sprocket covers off) show no visible tears or chaffing in the "lizard skin" looking wire cover.

Any theories on what could be causing this? I really don't want to remove stator cover if stator not bad and not necesary (I will retest again tomorrow, but weeks ago tested good per stator papers). Can something wrong with stator and/or stator wires cause the whole frame (basically) to read "hot" even if the stator wires are not connected to RR?

Totally baffled and frustrated

 

[posplayr]

Here is the remaining mystery to date in my ordeal:

b) Bike RUNNING, connect voltmeter lead to ANY ground, even the battery itself, makes no difference, there is this CRAZY fluctuation of readings.
* disconnecting any or all three stator wires makes NO difference at all.
* visual inspection of stator wires (with clutch & front sprocket covers off) show no visible tears or chaffing in the "lizard skin" looking wire cover.

Do you only have one lead from the volt meter connected?

If so, what are you doing with the other lead?

 

[Rkt-Rch]

Have been noticing the same thing with mine I think latley. I haven't verified anything yet, NO Time! Last week my Hiigh beam blew on the way home. For awhile I have been noticing the headlight/gauge lits acting funny. Did all the checks at beginning of season but looks like it needs to be done again... I think I'm going to spend some time on ALL the grounds again and check that R/R that was installed...

 

[shirazdrum]

Well, as someone who saw the voltmeter jumping around on this bike, I can swear I have never seen anything like that. All it takes is to hook up one probe to the positive or negative on the bike and hold the other lead in your hand (gloved hand, bare hand, on the ground, covered with insulation,...doesn't matter) and the meter starts going crazy.

My theory is that there is something wrong with the Stator (well duh) that sends a strong pulse to the system that causes this. A short that's not a short when the circuit is open but more like a spark plug jump to the ground. (I know that the 80v won't jump a spark like that, just trying to paint a picture here).

 

[almarconi]

I have followed the "drama" and "mystery" with your charging system for a couple of weeks. When Mr. Suzuki designed the bike, the charging system worked. There may have been some quality issues with some of the components but overall the system did what it was supposed to do. With that said, something is clearly wrong with your charging system. Be it the wiring, grounds or one of the components. There is really no "mystery" involved. Get a wiring diagram, clean and/or replace every connection, check your wiring and replace the stator and R/R.

That's it..no more drama..the charging system will work like it should. It is amazing to me how many extremely long posts are on this forum dealing with this issue. It's just not that complicated. The cost of a stator and an r/r is not that great that an endless amount of testing and trouble shooting are warranted on 30 year old electrical components.

 

[cavehamster]

Holding one lead in your hand? Sounds like an EMI issue, that is... maybe something wrong with the plug wires getting radiated. Have you tried running the bike in the dark and making sure yer not getting any blue sparks around the coils/plugs?

Regardless, holding one lead in your hand doesn't tell you anything more than how well you are conducting. How's it look with one lead well grounded, and testing with the other? What kind of multimeter do you have? How old is it, and have you changed the battery in it recently?

 

[shirazdrum]

Spark from the coil or spark plugs to the ground!!!
That sounds intresting. try that in the dark, we're getting somewhere here. take the tank off and run a long hose to the bike so you can see the coils.

The Voltmeter is good, i tested it with my meter when i was there and the result was the same.

It can be pulse of a very high voltage that causes the jump, i'm intrested to see the ignition system test result. Get your spark plug wires away from the block and test again, there's gotta be something.

 

[posplayr]

I have followed the "drama" and "mystery" with your charging system for a couple of weeks. When Mr. Suzuki designed the bike, the charging system worked. There may have been some quality issues with some of the components but overall the system did what it was supposed to do. With that said, something is clearly wrong with your charging system. Be it the wiring, grounds or one of the components. There is really no "mystery" involved. Get a wiring diagram, clean and/or replace every connection, check your wiring and replace the stator and R/R.

That's it..no more drama..the charging system will work like it should. It is amazing to me how many extremely long posts are on this forum dealing with this issue. It's just not that complicated. The cost of a stator and an r/r is not that great that an endless amount of testing and trouble shooting are warranted on 30 year old electrical components.

Mr Almarconi,
I have to disagree; you are completely underplaying these crutal results. I have it on good authority (my "sparks and magic class) that you can detect Martians using the open voltmeter technique described. In fact the needle bounce is a good indication of the proximity of the Martians as they move around in your garage.
I would say that doing the testing in a dark garage is a good idea. Since the Martians are invisible, they will not be able to see you in the dark either and so there will be a more even playing feild.
One thing to keep in mind is that Martians are attacted to dirty connections especially dirty R/R grounds. So please keep those connections clean. Working in a dark garage is also good, but best to clean those grounds before entering the dark garage. :-\\\
So with cleans grounds and a dark garage the Martians will not know if you are home, they will likely visit someone else that keeps the garage lights on working with open ended volt meters and dirty grounds.


Pos

 

[Rkt-Rch]

Agreed!!! But I hate to say it but I think I am going to see If I have any UFEP's around my coils.... My farther years back when I was a little boy!!! Showed me the (Martians) one night in the garage in the dark and low and behold they were there!!! Blue little #@!$$#!@@#'s Not Green but blue.... And this was on a 1972 V8 (largest production eng made at the time and front wheel drive) Cadilac Eldrado that the dealer had and could not fix... Before computers that is... Pops was a Eng/Mech and it only took him 10min that was it... The longest part was waiting for night to see it... and swapping the suspect wire. LOL Iv'e also fixed and trouble shot many this way.. If thier is any doubt about the caps/wires or connections change them, they might look fine and could even be new (yes new) the trons love to party....:lol:

I have seen this before and it is a pretty quick check, carbon/bad wires/ plug caps are all suspect.. In fact I think I'm going to change mine just to elimanate my Plug caps/wires,etc... All other cheks being done also....

 

[Speedo]

Thanks for the advice and the for the much-needed laughs PosPlayer! "Martian test" is scheduled for this evening.

I also came up with a theory, but I can't test it since my system is already infected with "martians" - what if you took any switched hot wire (on a bike without this problem) and purposely touched it with bare wire to the frame? Would that replicate this problem? Or might that blow something up?

BTW Shiraz, don't have to run extension hose from tank; just take seat off, slide tank back while still connected, turn 90deg and rest it atop frame that was under front of seat (strap it if your scared/anal) - works great for carb synching too. At least for my bike.

Almarconi - i do appreciate your "keep it stock" position and I do default to that a lot on most of my vehicles most of the time(e.g. new honda daily driver, old porsche, etc), but my other extreme is hot-rod the heck out of it if there is an improvement to be gained. With all due respect and for example, Mr. Suzuki also designed this bike with dual points and yes, the ignition system "worked" as well. Until it either broke a set of points (real real fun) or just slowly ran crappier and crappier within 500 miles or so. The Dyna S upgrade has been bulletproof for 15 years - like the difference between a Toyota Corolla vs. an old Triumph or MG.

 

[Speedo]

Night "Martian Test" results

Night "Martian Test" results

Test result: nada. nothing. Totally black. (I too know what I am looking for having witnessed the "martians" on my old '72 Mercury (351 windsor)).

Sonofagun of a Gunderson.....any other ideas? Is my theory viable? i.e. that maybe a switched hot somewhere has frayed to bare copper and is touching the frame?

What about the stator? Can stator, even though disconnected from RR, cause this somehow?

 

[shirazdrum]

No short on switched wires, you have a main fuse. Stator next.

 

[SqDancerLynn1]

Thanks for the advice and the for the much-needed laughs PosPlayer! "Martian test" is scheduled for this evening.

I also came up with a theory, but I can't test it since my system is already infected with "martians" - what if you took any switched hot wire (on a bike without this problem) and purposely touched it with bare wire to the frame? Would that replicate this problem? Or might that blow something up?

BTW Shiraz, don't have to run extension hose from tank; just take seat off, slide tank back while still connected, turn 90deg and rest it atop frame that was under front of seat (strap it if your scared/anal) - works great for carb synching too. At least for my bike.

Almarconi - i do appreciate your "keep it stock" position and I do default to that a lot on most of my vehicles most of the time(e.g. new honda daily driver, old porsche, etc), but my other extreme is hot-rod the heck out of it if there is an improvement to be gained. With all due respect and for example, Mr. Suzuki also designed this bike with dual points and yes, the ignition system "worked" as well. Until it either broke a set of points (real real fun) or just slowly ran crappier and crappier within 500 miles or so. The Dyna S upgrade has been bulletproof for 15 years - like the difference between a Toyota Corolla vs. an old Triumph or MG.

Hey I like those old Triumphs and MG's

 

[Speedo]

shiraz - ok, i reluctantly (cause i'm scared to do it) agree....stator cover must come off, stator needs to be eyeballed...I'm smelling a new stator order...

sqdancelynn-hey, no offense, I like the old MG's and Triumphs (and Jaguars, and Aston-Martins, etc) too. I'm just talking about the reliability factor (esp electrical, buttuh, pretty much everything really), which, u gotta admit, wasn't and still ain't very good. That's all I'm tryin' to say.

 

[79 sh850]

Holding one lead in your hand? Sounds like an EMI issue, that is... maybe something wrong with the plug wires getting radiated. Have you tried running the bike in the dark and making sure yer not getting any blue sparks around the coils/plugs?

Regardless, holding one lead in your hand doesn't tell you anything more than how well you are conducting. How's it look with one lead well grounded, and testing with the other? What kind of multimeter do you have? How old is it, and have you changed the battery in it recently?

I have to say that I am with the hamster on this one. With only one lead connected you may be measuring something, but to say out of hand that it is the R/R or stator is jumping to conclusions. The voltage test requires that both leads be connected to the circuit; this is the only way that significant results can be obtained. These are the numbers that matter.

I doubt very much that the leads of an multimeter would absorb so much RF from the coils that it would measure more that a millivolt. Either that or no one would be able to use an AM radio within a km from your bike since there would be so much hash. The electrical system of a bike is far from being flat DC. I wouldn't doubt it if the meter was picking up noise from the ground of the bike and giving a reading where there is nothing. I assume that both of these multimeters are digital. If you have access to one with a needle movement, I would suggest trying that in the same way to see if the needle sings, since if it did, that would truly be strange.

 

[posplayr]

A couple notes:

A DC volt meter (especially an analog meter) is designed to measure DC voltages by indicating the steady current flow through the meter. This steady state current flow through the meter is very small (sub mil-amps) but is required to deflect the needle. Anything else is undefined.

If the needle was deflecting from EMI (Electromagnetic Interference) then that would be energy radiated by the motorcycle and coupled into the leads of the voltmeter. The leads would be acting like an antenna. Since the phenomenon requires one lead to be grounded to the frame, I doubt this is the case.

While it is really only wild speculation, there are obviously current pulses (what the meter reads) flowing related to the change in potential between the bike and the ground as the motor cycle charges. So this represents charging doing any further quantification seems pointless. The measurement is not calibrated in any way as the meter is calibrated to measure constant voltages.

One would be well advised to spend time measuring voltage drop and cleaning grounds rather than conjecturing on what causes the needle to bounce.

The sparking that is common at the coils is a result of high impedance secondary components. This is usually bad wires. What happens is the igniter controls the primary current buy allowing current to flow and then stops the flow by opening the current path in the primary. When there is an attempt to stop the flow, there is a rise in the voltage across the primary which is further amplified in the secondary portion of the coil. This energy flow between the primary and the secondary is basically like a transformer. When there is current flowing through a wire, then there is a magnetic field. If there is a magnetic field around a piece of wire then current will flow. It is a sharing of the magnetic field between primary and secondary that causes the energy transfer.

So now if you have a high impedance wire (bad wire), the energy that gets launched when your igniter fires the primary cannot fully get to the spark plug as a portion of the energy bounces off the high impedance block. That energy reflects back up the coil wire and ends up arching across the primary leads.


At this point I'm not sure if it is coupling back into primary through the coil or just arching over but the effect is the same. Regardless this has nothing to do with charging and all to do with bad secondary ignition. Since we already know the phenomenon in 1.) above requires a connection to the bike frame we know that it is not EMI from the ignition.

No that I suggest this is a good idea, but if anyone was so inclined I suspect if you disconnect the R/R and start your engine that you will probably not see any bounce or at least a different bounce.
and has to do with shared magnetic field between the current flowing in the primary with the magnetic field of the current

charging and all to do with bad secondary ignition. Since we already knwo the phenomonom in 1.) above requires a conenction to the bike frame we know that it is not EMI from the ignition.

No that I suggest this is a good idea, but if anyone was so inclided I suspect if you disconnet the R/R and start your engine that you will probably not see any bounc or at least a different bounce.:hand:
and has to do with shared magnetic feild between the current flowing in the primary with the magnetci feild of the current

 

[Speedo]

1.While it is really only wild speculation, there are obviously current pulses (what the meter reads) flowing related to the change in potential between the bike and the ground as the motor cycle charges. So this represents charging doing any further quantification seems pointless. The measurement is not calibrated in any way as the meter is calibrated to measure constant voltages.

2. One would be well advised to spend time measuring voltage drop and cleaning grounds rather than conjecturing on what causes the needle to bounce.

3. That energy reflects back up the coil wire and ends up arching across the primary leads.

4. I suspect if you disconnect the R/R and start your engine that you will probably not see any bounce or at least a different bounce.

POSPlayer - thank you for your thorough response. Unf, its a bit technical for an idiot like me:-s My counter-points:

1&2. I disagree that identifying is pointless. Something has to be wrong. Remember that both Shiraz and I got a lot of bounce - two sep multimeters -when just trying to measure charging voltage across battery with bike running (Stator Papers test#1 Overall Charging system health). Shiraz's 850 was rock steady with BOTH meters, my $25 cheapy and Shiraz's expensive Fluke. We also tested main ground and it was perfect.

3. Night test = no sparks/total darkness. This rules out coil & wires.

4. Same bounce with stator disconnected from RR. Which should be same as disconnecting RR since w/o stator connected to RR, RR has nothing to do/regulate. Not to mention we actually DID test w/o RR when old RR died before I put new one on.


Shiraz said it can't be a switched hot grounding to frame since that would have taken out a fuse, SOOOOO....what does that leave? Only the stator I think. I am going to redo the stator output tests from Stator papers and report results / also see if anyone has other ideas before pulling the stator cover.

 

[posplayr]

1&2. I disagree that identifying is pointless. Something has to be wrong. Remember that both Shiraz and I got a lot of bounce - two sep multimeters -when just trying to measure charging voltage across battery with bike running (Stator Papers test#1 Overall Charging system health). Shiraz's 850 was rock steady with BOTH meters, my $25 cheapy and Shiraz's expensive Fluke. We also tested main ground and it was perfect.

.

What is pointless is using a DC voltmeter with only one lead connected (the other open) however, this is a hobby for most so have fun.

 

[cavehamster]

What is pointless is using a DC voltmeter with only one lead connected (the other open) however, this is a hobby for most so have fun.

Agreed. You're not measuring anything doing that, just the capacitance of your body vs the bike's electrics. Just like riding the motorcycle: try to keep both leads on the bike

Back up a minute, set your meter to resistance, put one lead on the ground terminal of the battery, and use the other lead to measure the ground terminal at various points around the bike. It should be very low, under 5 ohms at the very least. If you find one high, even though you have a good bite with your test lead, then you know you have a bad connection there.

 

[posplayr]

Agreed. You're not measuring anything doing that, just the capacitance of your body vs the bike's electrics. Just like riding the motorcycle: try to keep both leads on the bike

Back up a minute, set your meter to resistance, put one lead on the ground terminal of the battery, and use the other lead to measure the ground terminal at various points around the bike. It should be very low, under 5 ohms at the very least. If you find one high, even though you have a good bite with your test lead, then you know you have a bad connection there.

The primary value of the measurement is it's "entertainment value"