She won't charge while riding

[Midicat]

Good Labour Day afternoon everyone.

I have some trouble with my 1985 VR and I am turning to the wisdom of the forum for guidance.

Just took the scoot for a spin and it doesn't seem to be charging. Jumped it to start it, went for a 45 min scream in the country, got home and shut it off. No go.

The voltage needle was only half way up the meter during the entire ride.

After researching the troubleshooting options here, I proceeded to make the necessary voltage checks. Stator output is consistent on all three leads at idle and at 2000rpm. 45+ volts AC. Stator connection to R/R is clean. Voltage output from R/R is 13.75v DC. Voltage at battery at idle is 12.4v.

Could it be the battery just not accepting a charge? I have removed the battery and currently (pardon the pun) have it on a tender.

Any wisdom imparted would be greatly appreciated. I thank you in advance.

 

Thomas

 

[mountainmanVR]

My bet is the regulator-rectifier...

[Freebird]

And my bet is the battery. Not much help huh.

[Condor]

What's the voltage at the battery above 2000rpm?? If it's under 14.2-3vdc it could be the battery??? or the Rectifier.... LOL....

[mountainmanVR]

This was an issue exactly with my friends Venture, put in new battery, battery would never charge. Finally convinced him the rectifier was the problem, no charging issues since replacing.

[snyper316]

I know I know... Sounds like you got a gremlin Knawing at your stuff. get yourself a gremlin Bell.. that will help.... But I would almost have to say its either battery or Rectifier. Here is something I learned heat messes with things so maybe use a blow dryer aimed at your Rectifier and the motorcycle running and check the voltage.. I mean its worth a shot, but it also sounds like a possible bad cell in your battery..

[snyper316]

I'm actually confused why the voltage would be less at the battery.

[bongobobny]

Thomas, start bike, then remove one of the battery terminals. If the bike keeps on running with the battery disconnected then there is nothing wrong with your charging system, except if you have a problem like XV1100 had where it worked cold but not when it warmed up...

[Marcarl]

Did you do the stator check when it was hot or cooled off?

[Midicat]

Thanks Bob,

I will try that this morning.

 

Thomas

[Midicat]

Did you do the stator check when it was hot or cooled off?

 

Hi Karl,

Testing was done when bike was warmed up to operating temp.

 

Thomas

[Marcarl]

Hi Karl,

Testing was done when bike was warmed up to operating temp.

 

Thomas

 

That would be Carl with a 'C'.

Warmed up to operating temp usually isn't good enough, you need to ride it for few miles, so that the internals are right up there as well, and then check things right away, like in 5 minutes to be sure.

[CaseyJ955]

And my bet is the battery. Not much help huh.

 

X2. First step charge and test the battery. Not sure about a Venture but some bikes will cease to charge if the battery drops enough voltage.

[Midicat]

After a pleasant conversation with our friend Carl, a plan of action was determined. Here is what I did.

 

Full battery charge with charger. Not the battery tender.

Took stator voltage shortly after starting bike. 3000 rpm 56v AC on all three leads. Image one and two show first readings.

Went for a 15 km spin. Voltage gauge reads charging the whole ride. It would dip when slowing for a stop, naturally, but climbed to fully charging when cruising at 80kph. I should note that the needle on the guage never SNAPPED back to fully charging. It slowly crept up. Maybe 15 secs to get there.

Arrived home and immediately took voltage readings from stator output. Still 56v AC on all three leads at 3000 rpm. Yet needle shows not charging. Image three and four show readings upon return.

Took voltage reading from R/R side of stator connector and get a reading of 12v AC.

Output of the R/R was measured at 13.5v DC.

Could the stator connector be my issue? Should I solder those wires together?

 

 

Thanks for your help on this.

It's greatly appreciated.

 

Thomas

[bongobobny]

Well, you could try soldering the wires and eliminating the connector, it won't hurt. Seems as the issue is thermal. Confused with the 12VAC reading you got, just where did you see that?? Which wires?? The issue could be the connector and heat causing resistance at connector to rise. Hard soldering will verify/eliminate if that is the issue...

 

Once again, 'splain the 12VAC reading...

[Midicat]

Well, you could try soldering the wires and eliminating the connector, it won't hurt. Seems as the issue is thermal. Confused with the 12VAC reading you got, just where did you see that?? Which wires?? The issue could be the connector and heat causing resistance at connector to rise. Hard soldering will verify/eliminate if that is the issue...

 

Once again, 'splain the 12VAC reading...

 

Hi Bob,

The 12v Ac reading came from R/R side of stator connector while the bike was idling at 3000 rpm. Connector was connected to stator wires at the time of the reading.

 

Thomas

[bongobobny]

same across all 3 combination of wires?? You should have gotten the same readings you got from the connector for the stator!! Maybe THAT connector needs to be hard wired...

[bongobobny]

You weren't trying to read AC on the red/black wires, were you?? The red and black is DC only. If you are seeing AC voltage there then something is amiss with the R/R...

[Midicat]

Nope. Black/white wires were 13.5v DC. I did AC voltage on the three wires on R/R side of the connection. I just thought logically (which can be debatable in my case) that the voltage out of the connector would be the same as the voltage going into the connector. It's not.

 

Thomas

[bongobobny]

Well then there's your problem Thomas, yes they should be the same voltage on both sides of the connector, when connected. If you mean you were measuring the disconnected connector on the R/R side, you shouldn't have seen any voltage at all. The AC voltage comes From the Stator and travels down the wires thru the connector TO the R/R...

[mralex714]

Good Labour Day afternoon everyone.

I have some trouble with my 1985 VR and I am turning to the wisdom of the forum for guidance.

Just took the scoot for a spin and it doesn't seem to be charging. Jumped it to start it, went for a 45 min scream in the country, got home and shut it off. No go.

The voltage needle was only half way up the meter during the entire ride.

After researching the troubleshooting options here, I proceeded to make the necessary voltage checks. Stator output is consistent on all three leads at idle and at 2000rpm. 45+ volts AC. Stator connection to R/R is clean. Voltage output from R/R is 13.75v DC. Voltage at battery at idle is 12.4v.

Could it be the battery just not accepting a charge? I have removed the battery and currently (pardon the pun) have it on a tender.

Any wisdom imparted would be greatly appreciated. I thank you in advance.

 

Thomas

 

 

 

I thought the voltage from the stator should be around 100vac?

[bongobobny]

Output voltage from the stator is directly proportional to RPM. The faster the magnet spins inside the stator, the more EMF is generated. At idle the AC will only be around 20 volts AC or so, at 2000 RPM maybe around 30 - 45 volts, 3000 RPM around 60, 5000 RPM probably around a hundred or so. Sorry, do not have exacting figures, and it will vary some from stator to stator, and bike to bike depending on just how strong of a charge it is on the magnet.

 

The idea is as RPM increases, so does AC voltage, and the readings want to be fairly close on all 3 windings...

[camos]

What Bob is telling you about stator output is correct and within the average.

There seems to be some confusion about what connectors were being measured and where the AC and DC were being measured.

Hi Bob,

The 12v Ac reading came from R/R side of stator connector while the bike was idling at 3000 rpm. Connector was connected to stator wires at the time of the reading.

So the reading here should be at or about 60 VAC on both sides of the 3 wire stator connector.

 

Nope. Black/white wires were 13.5v DC. I did AC voltage on the three wires on R/R side of the connection. I just thought logically (which can be debatable in my case) that the voltage out of the connector would be the same as the voltage going into the connector. It's not.

The voltage out of the connector should be essentially the same as the voltage into the connector minus any drop due to poor connectivity. Any noticeable difference indicates a faulty connection. We are talking about AC voltage here.

 

DC voltage is measured on the two wire connector coming out of the R/R. The voltage here at 2500 RPMs or more should be around 14 VDC. A voltage of 13.75 at 2500 RPMs would be on the low side of adequate but it should still charge the battery. That is , of course, if the 13.75 v actually gets to the battery.

 

There are a lot of connectors involved in the charging system, both positive and negative. Any degrading in these connectors will affect the output level. So far you have focused on the stator which seems about right and the R/R output which seems a bit low. Have you pulled the R/R and cleaned the mount points? The mounts for the OEM R/R provide the ground connection and also act as a heat sink to the frame. A compromised connection here should affect the R/R ability to sense how much voltage is needed.

 

To me, a poor ground at the R/R most likely will create a low sensor reading and so the output would be increased to provide more DC voltage but since your R/R is putting out slightly less voltage than it should normally do it would appear the R/R is defective. Even if the R/R is slightly defective, some charging of the battery should take place if all the other connections are adequate. Clean all the connections between the stator and the R/R, the R/R and the battery and particularly the battery to ground, that's both ends.

 

Once that is done, whatever problems exist can be directly attributed to the components.

[yamagrl]

The red wire is basically a straight shot to the battery from the r/r.

 

The Black wire is a straight shot to the negative side of the battery with the only connector being on the smaller wire at the battery negative. This is the frame ground connector also but that doesn't matter right now because the r/r grounds directly to the battery through this connector and not to the frame.

 

All of the connectors involved are circled.

 

The blue arrow points to the red wire that branches off to the ignition switch, which further branches off to the radio to keep the presets, the clock and the emergency flasher. I doubt any of this would would effect charging.

 

Remove and clean both battery terminals. Separate the connector on the smaller negative wire at the battery and clean it the best you can. Use sandpaper or a small file or emery board and put it back together. If ground is the problem this is where it will likely be.

 

Also separate and clean the connector that is in the red wire coming from below the main fuse.

 

1. Set your idle up to 2500-3000 rpms.

2. Check the voltage cross the Red and Black wires at the r/r.

3. Then move your negative lead to the neg side of the battery and compare. Leave the negative lead here for subsequent readings

4. Next check the voltage at the connector (lower) side of the main fuse and compare.

You should see a small drop here that can be attributed to the other things running in the electrical system such as the engine ignition, lights, cmu, etc. so have as much turned off as you can.

5. Then check voltage at the battery side of the fuse and compare. ​From here on the voltages should remain the same

6. Then check it across the battery.

 

Make sure the connectors are clean, making good contact and not creating a voltage drop.

 

There is also the possibility of resistance in one of those wires. Checking voltage at each of the places I laid out will help in making that determination. If you find a wire to be the problem it's no big deal. It'll be easy make proper bypasses. I can guided you through it.

 

Heather

 

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Edited September 8, 2016 by yamagrl
Clarification