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Discussion Starter #1
This has probably been covered, but I thought would ask anyways. I recently picked up a non running, 1994 vn750 with about 7,5xx miles . PO told me he parked it after some electrical issues. He told me it rode great until one day it just died. He changed the Main fuse And the R/R. And it ran for a week and then died again. So he Parked it.. after i got the bike home I put a new battery in and as soon as I switch the ignition on It would blow the main 30amp. I found some melted wires but nothing shorted. I was curious so I unplugged the r/r and there was life! everything turns on and even the starter engages. But if I plug the r/r back in, the main fuse blows as soon as I turn the ignition on .... I tested the r/r with my multi meter and far as I can tell it checks out.. he also told me that the p/o changed out a faulty stator. Is it possibly that the stator itself is shorting out and blowing the fuse ? I’m pretty handy with a wrench but I tend to get confused trying to understand electrical any help would be great.
 

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Where were the melted wires? Black/yellow stripe are grounds.

Almost has to be the wires at the r/r, or the r/r itself.
 

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Discussion Starter #3
The wires I found were . The white wire and the brown/white wires at the bullet connectors behind the left side air filter box. The casing of the bullet connector was melted . I believe they are ignition wires but not sure
 

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Discussion Starter #4
Update: I just went out and tested the 3 wires coming off the stator with my multi meter set on ohms I put the negative prong on the plug wire and the positive on the engine block and got a solid connection on each wire ... does this mean my stator is shot ?
 

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Update: I just went out and tested the 3 wires coming off the stator with my multi meter set on ohms I put the negative prong on the plug wire and the positive on the engine block and got a solid connection on each wire ... does this mean my stator is shot ?
If the wires were unplugged, it means the stator is shorted to ground on all three legs. (which would be rare)

If the wires weren't unplugged, it's not a valid test.
 

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+1 to what Spockster said. The stator will measure as shorted if it is plugged in to the R/R, but should measure open line if unplugged.

You were right about the white and white/brown wires ... the white is voltage from the battery to the ignition switch, and the brown/white powers some accessories, but is also the monitor wire to the R/R, so there's definitely a short somewhere either in the R/R or the stator. You should get an open line reading from the positive lead on the R/R to the negative lead on the R/R. Likewise, there should be an open line reading from the positive lead on the R/R to all of the stator leads.

Unfortunately, the brown wire has little to do with those leads, and shouldn't really be carrying any current, just a voltage the circuit uses to see if the bike is getting the right voltage out of the charging system. If that wire is melting, there's likely a short in the the thyristors of the regulator causing an uncontrolled battery dump.

If you're willing to sacrifice another fuse, unplug the stator from the R/R, but leave the R/R plugged in to the bike's harness and turn the ignition on. If it blows, you're for sure looking at a bad R/R (and the stator should still be inspected, since they tend to die in pairs). If the R/R alone doesn't blow the fuse, you're looking at a bad stator.

Chances seem pretty high that your R/R has failed. If you have to replace, it's highly recommended to get a mosfet replacement instead of the OEM shunt style.
 

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Discussion Starter #7
Ok thank you for the input . I’ll do some more testing when I get home. The r/r was unplugged when I tested the stator Andrew it showed short on all 3 wires. I tested the r/r far as I could . I set my multi meter to diode, and tested each prong on the r/r one lead on positive, and read 1600-1700 on each. then I switch the lead to the negative and read only 500-600 on each. from what I read, It looked to me like it was ok. I ordered a cheap eBay stator to throw in for testing if it lasts cool if it dies hopefully it will last long enough to get the wiring figured out, and then Ill buy the better quality parts..lol.
Also I may have gotten some “luck” with this bike. hoping beyond hope I pulled The stator cover off and found that, to my amazement the previous owner had done. “the stator mod” so I shouldn’t have to pull the motor to replace it. I haven’t had to time disassemble it all to see how well he did but from what I seen it look decent
 

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Ok thank you for the input . I’ll do some more testing when I get home. The r/r was unplugged when I tested the stator Andrew it showed short on all 3 wires. I tested the r/r far as I could . I set my multi meter to diode, and tested each prong on the r/r one lead on positive, and read 1600-1700 on each. then I switch the lead to the negative and read only 500-600 on each. from what I read, It looked to me like it was ok. I ordered a cheap eBay stator to throw in for testing if it lasts cool if it dies hopefully it will last long enough to get the wiring figured out, and then Ill buy the better quality parts..lol.
Also I may have gotten some “luck” with this bike. hoping beyond hope I pulled The stator cover off and found that, to my amazement the previous owner had done. “the stator mod” so I shouldn’t have to pull the motor to replace it. I haven’t had to time disassemble it all to see how well he did but from what I seen it look decent
You’re in luck with the stator mod then. If the leads are shorted to ground it’s definitely shot. OEM is pricey but I get really good voltage readings even at idle.
 

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The stator has to have all three of it's leads unplugged in order to test properly. The three bullet connectors are in the area above the transmission, but behind the rear cylinder. Been a while, but I think that's the general location.
 

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Discussion Starter #10
The stator has to have all three of it's leads unplugged in order to test properly. The three bullet connectors are in the area above the transmission, but behind the rear cylinder. Been a while, but I think that's the general location.
Thanks I wouldn’t have known that but. They were all unplugged .. P.O cut off the bullets, and used but connections to wire to the 6 blade receiver plug that came with the R/R he put on. So all the R/R wires are unhooked when I’m testing.
 

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Thanks I wouldn’t have known that but. They were all unplugged .. P.O cut off the bullets, and used but connections to wire to the 6 blade receiver plug that came with the R/R he put on. So all the R/R wires are unhooked when I’m testing.
Ok, I got it now. Depending on what they did with the headlight trigger (branch off one stator lead) it could still have one stator leg connected to the Junction Box. Should only affect the testing on that one leg.

Does your headlight come on as soon as you turn the key on, or only after cranking/starting the engine? If it doesn't come on with the key, the one leg is still connected to the JB.
 

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Discussion Starter #12
Okay I wondered about that actually....not that I knew it was connected wrong. just thought somthing was funky .. The light doesn’t come on with the key. I thought that was strange... my first road bike was a vn700 and I thought for sure the light ran off the battery so that makes sense why it wasn’t coming on. So when I get home Should I clip that connection and test again ?
 

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Okay I wondered about that actually....not that I knew it was connected wrong. just thought somthing was funky .. The light doesn’t come on with the key. I thought that was strange... my first road bike was a vn700 and I thought for sure the light ran off the battery so that makes sense why it wasn’t coming on. So when I get home Should I clip that connection and test again ?
Well, it probably won't help. That is, assuming all the stator wiring is good, looks like it still has two legs shorted to ground.

Could also be something I'm missing, and disconnecting the headlight trigger could clear up the test.

We don't have any data for testing the stator while still connected to a circuit and my electrical theory is pretty half-assed. :wink2:
 

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Discussion Starter #14
Or maybe my old bike was messed up... After re reading your last post , and looking at the diagram. Im understanding that, there should be one leg split off, running to the jb and the light not coming on with just the key, is the way it’s supposed to be wired.and that I should only disconnect for testing. Sorry Sometimes it take me a minute lol
 

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Or maybe my old bike was messed up... After re reading your last post , and looking at the diagram. Im understanding that, there should be one leg split off, running to the jb and the light not coming on with just the key, is the way it’s supposed to be wired.and that I should only disconnect for testing. Sorry Sometimes it take me a minute lol
Yes you've got it. There's a headlight relay in the JB that gets triggered by the AC volts from one leg of the stator. That's the factory setup.

Many of us did the Blue Wire mod to bypass this relay.

Back to what Thorn posted ... When it's not charging and blowing the main fuse, that's usually a problem in the wiring, connections, or the R/R itself.

Seems like most of the tests for the R/R involve ohm and continuity tests rather than diode tests. But I haven't looked at the manual lately.
 

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Discussion Starter #16
🤦‍♂️ Well now i have a dilemma. I should be getting the replacement stator in the mail in the next couple days. So I started removing the stator, and it appears the p.o didn’t do the best job on the stator mod. It looks like the stator has been rubbing on the rotor, which would explain why it was shorted out so bad. The plate they used to do the mode and mount the stator is also much thinner than I was expecting, and appears a little bent. Also the wires on the pickup coils were so brittle that they snapped at the coil when I went to move them aside .....and to top it off... while I was removing the pickup coils I broke generator cover. Not my day.... anyways I can’t decide if it’s worth continuing to fix this bike, or put it aside as a parts bike... I bought it not running for 450$ and it had Been outside for over a year uncovered. So it needs new brakes. New tires carb work and so on plus a few other odd things. It also won’t shift past second gear. P.o says it allways shifted fine. but idk and I don’t want to put 1000$ into a bike that may not even shift once I get done bringing it back to life. Especially when I can go buy a running vn750 for that... what do you guys think... the main reason I picked this bike up was the price and the odo only reads about 7500 miles. But it’s starting to burn through the cash pretty fast.
 

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Ouch. Definitely an alignment problem, and a jagged cut on the case.

Sort of looks like one of the Xtreme mod plates, but the shape of the cutouts might be different, so maybe just homemade from the pattern that's available. Never saw one sunk in at the middle like that, any of the magnets have a chunk broken out?

Sitting in the weather is hard on the equipment. Hold off on repairs and see if there's another Vulcan available?
 

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Discussion Starter #19
Ouch. Definitely an alignment problem, and a jagged cut on the case.

Sort of looks like one of the Xtreme mod plates, but the shape of the cutouts might be different, so maybe just homemade from the pattern that's available. Never saw one sunk in at the middle like that, any of the magnets have a chunk broken out?

Sitting in the weather is hard on the equipment. Hold off on repairs and see if there's another Vulcan available?
That’s what I was thinking too thanks. And no chunks missing out of the stator, just real scratched up and that little piece of metal sticking out of The one coil leg not sure if it’s a broken wire from the windings or what ... such a shame people don’t take better care of their stuff. I hate to see such a low mile bike, that still looks half way decent be used for parts but is what it is.
 

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Doesn't look bad in the pic, I see aftermarket pipes, relocated rear turn signals, and the seat/backrest has been changed. Also has a crash bar/engine guard, maybe for a larger Vulcan, not sure, adapted Harley piece? I guess only you can decide if it's worth saving.

I won't post the list, but my bike was in worse shape and got all the mods before the first ride. Was able to find my parts here and on ebay, so I saved a bunch. Looks great today and I could still sell it for a reasonable price and get most of my money back. Have also put 6000 trouble-free miles on it. I paid $600 for it in 2013, it's a 2003.

Was thinking the rotor hit one of the stator coils and caused that kink in the mod plate.
 
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