Where'd My Volt Go!?

[Teague]

Where'd my volt go!?

Over the past three months I've been on a quest to revitalize my 03VFR. New coat of paint, figure out the pesky t-stat issue, and of course re-vamping the electrical system so it doesn't try to set anything on fire.

Paint? Check.

T-stat issue? Check.

Electrical system overhaul? Check... wait a minute! My frustration went to warp factor 10.

I beefed up all wire associated with charging / starting. I re-ran 14 gauge wire from my stator to R/R which replaced the pesky connector that likes to grill out. I changed out the OEM R/R for a 05 Yamaha R1 RR. All of my wiring is soldered, heat shrinked, and then put in protective high temp sleeves (overkill but it sure looks nice).

I took a systematic approach to this overhaul and tested everything along the way. I hate making 25 changes to a project and then turning it on to find that I missed something or a part borked along the way. I took my time and checked my voltage throughout the project. During my test runs the voltage was a rock solid 14.4v with the motor running, didn't matter what I turned on / off. I gave the electrical system the a'okay and went ahead and put everything back together.

Fire it up last night after getting the last bit of air out of the coolant system and the voltage at the battery dropped an entire volt.

Battery Voltage: 12.76v

Cranking Appearance: Sluggish from time to time

Idle Battery Voltage: 13.45-13.65v

5k RPM Battery Voltage: 13.5v

Ideas where to start? The battery is a OEM Yuasa which I've been using for 2 yrs now. I tried a battery from my SV and it showed the same symptoms (both are older batteries though).

Replace battery? Stator? My new trusty R/R already on its way out?

EDIT - If the battery is fully charged.... is 13.6v proper voltage?

[BOBINOTTAWA]

I would start by getting the battery load tested. Since the recharging system seems to be operating well (14.4V). The sluggishness on 'some' starts indicates a battery not holding enough charge even though the Volts are okay. Is there a pattern as to when the starts are sluggish? Is it just different than when it was new.

You indicated that it lost a volt on your last start after the air-burp. Could this have been due to quite a number of starts will not-enough recharging time?

Do you have a volt-meter mounted on the dash? (this was helpful to me diagnosing the monitor-wire RR problem). My recharging voltage spiked to about 15.5V when the RR got hot.

All in all, I would get a new battery if nothing becomes obvious.

[FotoMoto]

Are the before/after readings being taken at different locations? My wired in meters from the harness can read up to a volt lower than my hand held meter at the battery.

[sckego]

When I was trying to test my charging system, one of the first diagnostics listed in the shop manual is a 'leak test' that measures the amount of current leaking from the battery to ground. Maybe your changes affected this and increased the current leak?

[Tightwad]

I am betting on a stator with 1 bad leg. I believe I have a similar issue....I had a smoked connector, and charging voltage has only been 14.1, where is was 14.6. I also see charging voltage drop when i turn my grips on by .5 volts, which is more than is justified by 25 watts of use or so.

And yes, you would think the guy who loves Electrical would have figured out the answer by now, but I have been busy/lazy.....

[vtecal]

I am betting on a stator with 1 bad leg. I believe I have a similar issue....I had a smoked connector, and charging voltage has only been 14.1, where is was 14.6. I also see charging voltage drop when i turn my grips on by .5 volts, which is more than is justified by 25 watts of use or so.

And yes, you would think the guy who loves Electrical would have figured out the answer by now, but I have been busy/lazy.....

+1.

The same thing happenned to me last year--400 miles from home. The previous day had voltage at 14.3 in the morning, then dropped to 13.6 by the afternoon. The bike cranked fine the next morning but I was only indicating 12.9 at 5K RPM. I have an in dash voltmeter---I headed home, and by the time I was home the voltage was indicating 11.2. Thank god I carry a spare key--I didnt shut off the engine when I refueled...and I kept the RPM above 5K for the rest of the ride so I could get at least 11 volts.

1/3 of the stator was fried--it looked like a blowtorch had been applied directly to the windings. The recall was done and I have tightwads harness mod. A new stator and oil change later it works like a champ and holds 14.3v.

[FJ12Ryder]

This may just be me but I would have used 12 gauge wire and not 14 from the stator. 14 seems a bit small to me. This shouldn't affect the voltage to the battery, but the larger wire seems like a good idea.

[FotoMoto]

I kept the RPM above 5K for the rest of the ride so I could get at least 11 volts.

You didn't mention if you did this too but unplugging the headlights (in the day obviously) will get you a lot more range. On the other end of the spectrum when the r/r is overcharging, I once read about on rider on a trip who stopped and wired in d/c plug, purchased a d/c powered thermos or somesuch and used that to suck up the excess draw until he could get to a dealership.

[spud786]

I dont think its the battery since you tried the other, but with these AGM's, they can read good voltage yet have little output.

13.6v in a motor off condition, sounds high, even a brand new yuasa for me fully charge reads about 13.16 in an off condition.

But you out to be getting over 14 volt just above idle, atleast I do.

You've done alot of modding, so I cant add more, cause the stock wiring I've had no trouble pushing 55,00 mile, and even running an electric vest and radar unti, I read 13.8 to 15 volt, while riding, with completely stock wiring.

[JayWalker]

Geez, all this electrical talk is giving me anxiety. :blink:

anxiety Show Spelled Pronunciation [ang-zahy-i-tee] Show IPA

–noun, plural -ties. 1. distress or uneasiness of mind caused by fear of danger or misfortune: He felt anxiety about the possible loss of charging voltage.

Now I'm off to the garage to take measurements. :mellow:

JW

[Teague]

I'm going to check the stator output tonight to see if one of the windings did fail within the past week.

It's been running fine, but I'm going on my early Spring mountain trip and the last thing I want is to be stuck in the middle of no where standing on some awesome twisties.

I am betting on a stator with 1 bad leg. I believe I have a similar issue....I had a smoked connector, and charging voltage has only been 14.1, where is was 14.6. I also see charging voltage drop when i turn my grips on by .5 volts, which is more than is justified by 25 watts of use or so.

Smoked connector? Check

0.5v drop when I turn on my Symtec grips? Check

To replace a stator do you have to replace the flywheel at the same time or just the stator itself? (23,000 miles on a 2003 6th)

[sckego]

To replace a stator do you have to replace the flywheel at the same time or just the stator itself? (23,000 miles on a 2003 6th)

Just the stator. There's a pretty good how-to on here somewhere. I did it myself a few weeks ago (original one crapped out at 42K). It's not too bad of a job; I think the biggest PITA was routing the wiring through the frame to the other side. Next time I'm lubing the whole thing up with vaseline before I try and pull it through. Having a long screwdriver and flashlight helps too, so you can poke at it when it gets stuck right in the middle.

[Teague]

Well the question is.... assume one of the legs is dead. Will it at least survive until another leg goes out?

It won't be too cold so I will not be using my heated grips so all it should be doing is re-charging my cell phone and the main battery.

I don't have time to replace the stator at the moment.

[spud786]

Well the question is.... assume one of the legs is dead. Will it at least survive until another leg goes out?

It won't be too cold so I will not be using my heated grips so all it should be doing is re-charging my cell phone and the main battery.

I don't have time to replace the stator at the moment.

if any leg goes the whole thing is useless, it will not operate correctly

shouldnt have to touch the flywheel, 03 models should have the latest flywheel up grade, the stator is housed in the cover.

Make sure you do a Thorough check before replacing, like the ground test will normally catch the typical failure. Set you meter to high level of ohms.

should be infinte from any leg to ground on the yelllow wires

Not sure why you would not want to use the actual RR, instead of an utested model from another bike on a 6th gen, the 6th gen RR is very sound, not like the 5th gen frequencies of years previous.

[Teague]

I went ahead and put my OE R/R back in just to get back to the basics.

Battery voltage bike off: 12.7v

Battery voltage bike on / motor off (fuel pump off): 12.5v

Battery voltage bike on / motor off (fuel pump on): 12.3v

When the bike starts I do see voltage down into the 9v range. (Battery is two years old)

Battery voltage bike on (low beams): 14.2v

Battery voltage bike on (high beams): 13.5v

Increasing RPMs never lets voltage go above 14.2-14.3v.

Did a diode check on both positive / neutral legs of the R/R to each stator input - Checked out fine (Good)

Resistance on the yellow wires from the stator start at 0.03 and fall to 0.00. (Good)

AC output with the stator unplugged were a very symmetric 25 VAC while 50 VAC at 3,000 RPM. (Good?)

AC output with the stator plugged into the RR were a very symmetric 10 VAC at idle and throughout RPMs. (Not sure on this one)

I do have the updated wiring harness that was replaced during the recall.

So the question is... it's not perfect... but would you take this bike on a mountain trip this weekend?

[FotoMoto]

Where'd my volt go!?

During my test runs the voltage was a rock solid 14.4v with the motor running, didn't matter what I turned on / off. I gave the electrical system the a'okay and went ahead and put everything back together.

I went ahead and put my OE R/R back in just to get back to the basics.

Battery voltage bike on (low beams): 14.2v

So you're worried because you're seeing a .2v difference between two entirely different r/r's one of which isn't made specifically for your bike? :dry:

I'd install a voltmeter if you haven't, carry one of them as a spare, relax and enjoy your trip.

[spud786]

If your stator was dead, you would even get 13volt while running

I say charge the battery good, and if you doubt replace it, but sounds like your are charging.

a quick test on the battery, charge it fully, turn the lights on for a few minutes (like 3), then see if there ample oopmm to turn the motor over , if not get rid of the battery.

[Teague]

I checked resistance from my battery positive terminal to the Honda R/R red wires.... freakin 1000 ohms!

Then I checked from the battery to any other positive connection (tail light, turn signal, etc) and it is again, just about 1000 ohms.

Is that amount of resistance normal or far from it?

[Tightwad]

I checked resistance from my battery positive terminal to the Honda R/R red wires.... freakin 1000 ohms!

Then I checked from the battery to any other positive connection (tail light, turn signal, etc) and it is again, just about 1000 ohms.

Is that amount of resistance normal or far from it?

This is where the VFRness excels....very little resistance as it uses 8 gauge wire for most of the route, then 12 gauge wire to each red wire.

[Teague]

I agree that there should be an larger gauge wire going to the R/R, but why would I be seeing 1k ohms going from battery to tail signal positive?

[spud786]

I checked resistance from my battery positive terminal to the Honda R/R red wires.... freakin 1000 ohms!

Then I checked from the battery to any other positive connection (tail light, turn signal, etc) and it is again, just about 1000 ohms.

Is that amount of resistance normal or far from it?

well, have to check all the mechanical connections in that wire route from battery to RR. Its not a vfr thing , every bike I've had this has to be done, and checked routinally.

[Tightwad]

I agree that there should be an larger gauge wire going to the R/R, but why would I be seeing 1k ohms going from battery to tail signal positive?

Battery to tail light goes through the ignition switch, so there is lots of resistance possible in that routing (and small wires as well)