Charging issues - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
Electrical
Where does this wire go?
Includes Electrical mods, Lights, Stator,
Rectifier, Diagrams, etc

 1Likes
  • 1 Post By One1
 
LinkBack Thread Tools Display Modes
post #1 of 9 (permalink) Old 06-27-2018, 08:03 PM Thread Starter
Junior Member
 
Join Date: May 2010
Posts: 20
iTrader: (0)
 
Unhappy Charging issues

I was unfortunately in need of a tow home today from work on my VN750. I have about a 30 mile ride into work and noticed in the last half mile some "funniness" like I had hit reserve, but I had a full tank and was already in the reserve position. I chalked it up to erratic wind, however when I got nearly to my parking space it felt like a cylinder cut out for an instant and recovered. At lunch I went out to see what was up with it and found that starting it was not going to happen, the battery was drained pretty well. The battery is a Sears die-hard from last year.

In any case, I went in and grabbed a little lead acid battery from work (not a automotive one), let it sit a minute charging myself and I was up and running. I set the choke pretty high to keep a nice high RPM and started heading home thinking the battery was bad. I made it about 2 miles and it died in an intersection, in the end I ended up on a flatbed being towed home.

Upon getting home, the battery was 11.x volts, so too low. I pulled it and threw it on a charger, it was taking a charge very well. I stuck in a 12V (nominal 16v) supercapacitor bank I'd made (long story, I ran the bike off it for years for starting) and although I would start in the 14+ volt range, I could watch the voltage drop until it stalled. No charging.

I've been going through the forums and youtube videos about Stator failures and I was in the .6ohm range between any of the yellow wires, HOWEVER, my voltmeter indicates around 13.85 Mega Ohms between any phase and ground, which supposedly means a bad Stator. When I run the bike though, with the stator wire harness disconnected, I get good voltage out of it and it goes up proportionally with RPM. I read somewhere else about using a 12v test light to see if there was voltage flow, and ran this in line with the milli-ampre range on the voltmeter. No voltage was passing between any phase and ground.

I don't understand the 13.85 Mega Ohm resistance between ground and any of the phases.

In any case, The wire harness looked pretty nasty with corrosion, so I was down there cleaning the connections with Hoppe's No9 (had it handy), pipe cleaners, and a bronze brush.

Upon hooking it back up, it started AND I get charging. What's normal? I was 14.x volts @2000 RPM, but low 13.xV at perhaps 1100 RPM ( idle). The bike was running a bit slow for a bit and I noticed that when it would drop below about 1000RPM the voltage was insufficient to really charge it, meaning the low end of 12.x volt range.

I don't really trust the bike now for going to work (main use), and I'm not sure what to check next. I have a feeling that the ignition switch might have some issues, as I've had a few cases where I hit the starter and "nothing" happens until I take the key out, fiddle with it, put it back in and then can start.
roamergrg is offline  
Sponsored Links
Advertisement
 
post #2 of 9 (permalink) Old 06-27-2018, 10:30 PM
Senior Member
 
Spockster's Avatar
 
Join Date: Nov 2012
Location: WV
Posts: 6,280
iTrader: (5)
   
That's decent charge volts, but have you ohm and volt tested it hot, fully warmed up? They can fail after full warmup.

The continuity to ground should mean it's toast.

You didn't check AC volts?

2003-21k mi
Shaved w/UniPK92+Stock Jets-TPE/MOSFET-Shinko Tires-AGM batt-bags-chrome-LEDs...more
__________________________________________________ ____________
Repair Manual: http://www.mediafire.com/file/mj7z81..._Catalogue.pdf

Owner's Manual: http://www.mediafire.com/file/nscb5f...ers+Manual.pdf
Spockster is offline  
post #3 of 9 (permalink) Old 06-28-2018, 02:18 AM
I'm a rider
 
One1's Avatar
 
Join Date: May 2014
Location: Signal Mountain, TN
Posts: 753
iTrader: (0)
 
Garage
Connector going into the RR usually melts a tab and needs cleaned or replaced. Typically it will backfire when starting to warn you of impending failure, but not always. If cleaning the connectors helped you've likely found the suspect. Ride it and see.


1981 KZ750
1988 Vulcan VN750 (red)
2005 Vulcan VN750 (silver)
(2) 1994 Vulcan VN750 (red)

Engineering solutions for the VN750 Community.
One1 is offline  
 
post #4 of 9 (permalink) Old 06-28-2018, 10:59 AM Thread Starter
Junior Member
 
Join Date: May 2010
Posts: 20
iTrader: (0)
 
I will once I get it back on the road. I got it running in the garage last night but I haven't road-tested it yet.


Does anyone have a good solution for a cheap, reliable, waterproof, voltmeter I could hook up ( a display/ LED) to add this to the bike? I would rather like to know when I'm charging or not...
roamergrg is offline  
post #5 of 9 (permalink) Old 06-28-2018, 11:39 AM
Senior Member
 
Spockster's Avatar
 
Join Date: Nov 2012
Location: WV
Posts: 6,280
iTrader: (5)
   
There's a lot of voltmeters in different styles on ebay for $10-15. Digital, bar graph, some with USB charging ports, a lot more to choose from than there used to be.

Had to go 17 pages deep to get above $10 .... https://www.ebay.com/sch/i.html?_fro...c&rt=nc&_pgn=1

2003-21k mi
Shaved w/UniPK92+Stock Jets-TPE/MOSFET-Shinko Tires-AGM batt-bags-chrome-LEDs...more
__________________________________________________ ____________
Repair Manual: http://www.mediafire.com/file/mj7z81..._Catalogue.pdf

Owner's Manual: http://www.mediafire.com/file/nscb5f...ers+Manual.pdf
Spockster is offline  
post #6 of 9 (permalink) Old 06-28-2018, 12:26 PM
Members who have donated towards server costs
 
Join Date: Apr 2018
Location: southern, western, middle Tennessee backwoods
Posts: 273
iTrader: (0)
 
This one is on it's way to me.

We'll see if it'll do the job after awhile.

https://www.ebay.com/itm/Waterproof-....c100290.m3507

"I need yo clothes, yo boots and yo motocycle."- Uncle Bob
roadpouring is offline  
post #7 of 9 (permalink) Old 06-28-2018, 12:40 PM
I'm a rider
 
One1's Avatar
 
Join Date: May 2014
Location: Signal Mountain, TN
Posts: 753
iTrader: (0)
 
Garage
Quote:
Originally Posted by roamergrg View Post

I don't understand the 13.85 Mega Ohm resistance between ground and any of the phases.
I've been able to get a light resistance reading from inducted potential off magnetized structures using very sensitive meters. While you shouldn't be able to get resistance from a circuit that isn't complete, the transformer proves that you can create an inducted bridge across a field of energy, mimicking a wired connection. The meter reads the ground potential against the self powered DMM from the positive of it's internal battery. An analog meter wouldn't show resistance.
ubertalldude likes this.


1981 KZ750
1988 Vulcan VN750 (red)
2005 Vulcan VN750 (silver)
(2) 1994 Vulcan VN750 (red)

Engineering solutions for the VN750 Community.
One1 is offline  
post #8 of 9 (permalink) Old 06-28-2018, 11:10 PM
GDI
Senior Member
 
Join Date: Aug 2017
Location: Madison, WI
Posts: 167
iTrader: (0)
 
Here's the one I installed when I changed out stator and regulator/rectifier. It's a little pricier than some, and doesn't show actual voltage. Still is pretty comforting seeing that dull green glow while she's running down the road!

GDI
GDI is offline  
post #9 of 9 (permalink) Old 06-30-2018, 12:01 PM Thread Starter
Junior Member
 
Join Date: May 2010
Posts: 20
iTrader: (0)
 
I put things back together a bit and went for about a 3 mile ride, battery voltage started at 12.70V (took it off charger yesterday), was charging a little over 13V at idle upon return. I let it sit for a good 30 minutes and it's at 12.9V now...

I will be watching it on longer rides for sure! Worried it might cut out at temperature as suggested.
roamergrg is offline  
Sponsored Links
Advertisement
 
Reply

Bookmarks

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

Once registered, your User Name"cannot be changed". We can make exceptions within 7 days, but after that, it is set in stone.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome