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.

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?

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.

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...

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

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'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.

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

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.