electrical help (charging issue)

Hello everyone. So I have been trouble shooting my electrical issues for a while now and I thought I was finally at a point where everything was working. And initially it seems to be.

I have replaced my stator, rectifier, and installed a vfrness.

So when I start the bike up everything is good, I monitor the voltage with a voltmeter I installed. With the choke on I am reading a little over 14.0 volts which I assume is normal. When I turn off the choke the voltage comes down a bit and fluctuates between 13.1-13.5.

When I ride the voltage stays up around 14.1-14.2

The problem occurs after I have had the bike running for about 15 minutes. Either riding or sitting still the voltage drops off and starts running on just the battery power.

Yesterday this happened and after a minute or 2 the charging system kicked back on. Has anyone had a similar issue? Wondering if the rectifier is getting too hot

Thanks!

 

Sounds like a hot short of some kind. Either the rectifier or a phase on the stator. You said you replaced the rectifier and stator, but you didn't say what you replaced them with. Did you get an oem stator and an rr kit from roadster cycle? If not I would rule those parts as questionable.

Even Rick's RR/Stators aren't really that great, I have seen Rick's stator's putting out an extra 20VAC over oem before. If you upgraded to an FH020 kit from roadstercycle, the RR will not get even slightly hot. Stator temperatures can get pretty hot in traffic, unless you upgraded to a series type rr (SH775 or SH847) which unloads the stator somewhat depending on current demand.

You can do a hot stator test, by getting the bike hot enough to repeat the problem and quickly disconnecting the stator from the rr and while the bike is still running do an AC voltage test, to see if one phase is dramatically lower than the other two, then shut the bike off and do a stator resistance test and finally an rr diode test. Try to do it fast before the bike cools down. You might have to give it a few shots.

 

Please see this thread .....

http://vfrworld.com/forums/showthread.php/52131-The-Drill

 

Thanks so much for the reply. I didn't really know that a hot short was a thing but makes sense now.

To clarify I am using a r/r from Rick's Motorsports and the stator was installed by a honda shop but does not appear to be an OEM replacement. The wires are very different looking, sort of a reddish braided shielding on the outside of the wires coming off of the stator.

I will reproduce the failure and check the stator and rectifier. I won't be a happy camper if its the stator

 

I've got a Rick's MOSFET with 40K miles and counting. It's survived 4 coast to coast USA crossings and hasn't left me stranded once. I'd say that's "pretty good"

 

Lucky you. Rick's rr and OEM stator?

Sent from my Nexus 6 using Tapatalk

 

Also while you're in there, be sure to check the rr to stator connector terminals. Those are a big failure point and like to burn up. Most people simply cut them out and solder across.

The thing with hot shorts is, material usually expands when it's hot and different materials can expand at different rates. So say for instance a stator when heated, the metal windings expand at a different rate than their insulation and a crack develops, that only shorts when hot.

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Always check connections UNDER the starter solenoid plug whenever there's a charging problem, looking for melting or burning.



A frequent and common fault on almost every VFR. :grey:



One quick fix:

 

Same for me. I love the r/r from Ricks. I'm at about 15k on mine. They are way more expensive than the other after market junk out there but a shop I visit every now and then swears by Ricks and they've been in business for a bit.

 

If its working then stops then working. Its going to probably be a short or bad r/r. I use a Ricks r/r myself. I noticed some naysayers here on it but one guy is rocking with it and I've been doing great with mine. Thr first garbage one I put in would work, get hot, overheat, shut off for a while and then start working again. One day it broke open, splattering its oil on my bike and leaving me stranded once the battery died. If not, follow the wiring to ensure you're getting a good connection. You can also use a volt metter for this. If you disconnect the plug from the r/r and use a volt meter on the lowish DC setting on 2 of the 3 yellow wires at a time. You should run around 50 volts and it should increase as you crank the throttle. If its good than problem is at the r/r and/or the wiring from r/r to batter (red and green wires) which charge the battery. You can ac volt meter the green/red wires to what they are suppose to connect to see if they are transferring a priper charge. If it doesnt increase well than you know its the stator or harness between the units. Unplug the stator at the main connected under the right mid panel and test those 3 wires the same as last time. Passes, good stator, fails, problem with the wiring to the harness.

 

Good info, but did you forget to mention that the stator voltage tests must be done with AC volts only and range from about 8 at idle and up to 65 AC volts at 5000 rpm ?

 

So I checked a few things yesterday. At the plug for the R/R I was getting about 9-10 volts for each wire at idle and it went up to ~40 volts at 5000 rpm. I want to believe that the regulator from ricks is good but it does get very hot. I was thinking about getting a MOSFET unit and wiring it in since those seem to stay cool and constant.

I had my battery on the charger and took it off 2 days ago. The battery voltage was at 13.1 and during idle it was at 13. When riding or reving it would max out at 14.0. Once again after it got hot and I rode it for a few minutes the voltage dropped and I was able to test the stator. The voltage across the battery was reading 12.4 when the voltage dropped. I was getting the same numbers from the stator so I don't think that is an issue. There is no melting or corrosion on any wires that I have found so far.

Is it possible for a faulty starter relay to cause this sort of problem? When i installed my vfrness I didn't connect the power wire to the relay for a while but the bike would still run. I have now wired it in and it runs about the same.

Thanks for all the help! Hoping I can get this all sorted out soon.

 

crazy question:

how old is your battery?

 

good question, it is pretty new. less than a year old

 

Ac volts after rec/reg changes it. Dc at the stator and rec connector (stator wires) red/green is AC and cont.

 

Yeah, i know that but wus drinkin' !

 

^ u baddie Hows Barf-ah-Low, may be doing a NYC trip with the old lady and 1yr old baby in toe, cross your fingers for me. No more thread jacking, I promise, I got an entire new wiring harness in my 91 bike, installed it years ago, soldered up the three yellow from the stator (eliminated that plug) and have a Roadster RR where the black/red go directly to the battery terminals. All is good with my 93 too, same set up, minus the new harness. Cheers.

 

so both the red wires from the new vfrness are going straight to the battery? I thought the one had to go into the starter relay