Wildly fluxuating voltages - Stator failure

[kaitsdad]

On my way to WFO8 last month, I started seeing voltages all over the map on my Escort X50. Kind of freaky. Readout would dance between 12.7 to 13.2 VDC, with frequent dips into the low 11's, and even peaks to 14.2. My first stop was at Ignacio's house in Pasco - a short 1120 mile day of which most of my time was spent watching the damn readout.

The next morning I researched it on this forum, and found two posts (Warchild and TwoWheelTiger - R.I.P. Andre) that commented on how a dirty or faulty connection in the stator output could result in these readings - so being parked in Iggy's shop, I found some contact cleaner and hosed down the stator output connections. Once dried, started her up, and all seemed to be fine, showing a steady 14.1 VDC at idle.

Heading out later that morning, things were fine for about 1 mile, then it started again. Iggy and I had discussed doing a really twisty side trip, but not wanting to be astride a 650 pound doorstop in the middle of eastern Washington, we truncated and did the most direct route.

Following WFO8, I headed for Garden Vally, Idaho to spend Sunday night with my aunt and uncle. VDC readout doing the same thing. Steady when cold, as soon as warmed up, all over the map.

Monday I departed Garden Valley, VDC again doing the same thing - steady when cold, warmed up, dancing display.

Due to the daytime travel and the high temps, I'm not running any farkles except the cruise, radar, and two 2730's -and occasional fuel pump, so aggregate wattage load at peak use would have been under 50. Not a problem, so I'm thinking I've got a failing display.

No problems starting, nothing dimming, battery seems to be staying up.

So - make it home, and except for the dancing numbers, everything seems fine.

So I finally get around to testing it -I dig out my DMM, and do a temporary Datel installation - and all three voltage meters agree.

Using the incredible amount of information on the stator from IonBeam (Thanks, Alan !!) I start her up, pull the stator connector, and check across the legs for AC output - and all three legs are reading >50 VAC. This is at warm idle. I have my son hold the throttle at 2500 rpm, and get even better numbers.

Stumped. WTF is happening here? Number 1 son and I walked away from it at this point. He headed back to his place, and I decided to mull things over a wee bit.

Thinking about the pattern displayed during my trip, the numbers tended to be good until it heated up -

So - a few days later using a ty-wrap as a throttle lock, I started up the bike and let it run at 3K, running my garage fan to push heat out of the garage, and waited until there were 7 bars showing on the display, and the cooling fans had cycled once. I pulled the connector, and all three legs were sub 30VAC.

Heat sensitive. Had I ignored it, it most likely would have done a teats up failure at some really inconvenient location, instead of my garage.

New stator and gasket is enroute from Gary McCoy at Mondak, covered under YES.

I'll take pics and such of the swap out and the failing stator. More to follow in a couple of weeks.

 

[Fred W]

Very interesting.

Assuming that it is the stator when you get it uncovered, could you tell us what sort of added electrical loads you put on that stator before the failure? Do you use a lot of heated clothing, heated grips, big ass lights, all of the above, etc. It sounds like you do not yet have a permanent Datel voltmeter installed, so what sort of voltages had you been seeing on the Escort when you put a full load of accessories on it. In other words, how low would you go before shutting off some other stuff?

 

[dcarver]

Was the 30 VAC stable? If so, what caused the fluctuating final VDC readings? Probably fluctuating ACV coming out of the failing stator, heat induced. Or, assuming ACV was 30 and stable, perhaps the value is at the lower threshold for the RR to produce a steady but low DCV output?

Ahhh, too much wondering. Replace that stator then test again! Ain't it great when you finally break down in the garage?

 

[ionbeam]

...assuming ACV was 30 and stable, perhaps the value is at the lower threshold for the RR to produce a steady but low DCV output?...

If the stator test was done correctly with the stator connector unplugged, k'dad was seeing a totally unloaded voltage reading. When plugged into the electrical system and under load the 30 VAC would certainly get loaded down even further. The ECU measures the voltage of the electrical system and plugs that number into the FI equation. The ECU, running lights, meter assembly, coils, injectors, headlights, fuel pump, (ABS computer) (PCIII) (GPS), assorted wiring system relays, etc are all drawing current when the stator is plugged in. This will quickly heat the stator and things go down hill quick.

The voltage rectifier will work down to ~2.8 volts. The output of the rectifier section going to the voltage regulator is probably below 14.6 volts, so all the Silicon Controlled Rectifiers (SCR) in the regulator will be off letting the system voltage fluctuate.

 

[kaitsdad]

...assuming ACV was 30 and stable, perhaps the value is at the lower threshold for the RR to produce a steady but low DCV output?...

If the stator test was done correctly with the stator connector unplugged, k'dad was seeing a totally unloaded voltage reading. When plugged into the electrical system and under load the 30 VAC would certainly get loaded down even further. The ECU measures the voltage of the electrical system and plugs that number into the FI equation. The ECU, running lights, meter assembly, coils, injectors, headlights, fuel pump, (ABS computer) (PCIII) (GPS), assorted wiring system relays, etc are all drawing current when the stator is plugged in. This will quickly heat the stator and things go down hill quick.

The voltage rectifier will work down to ~2.8 volts. The output of the rectifier section going to the voltage regulator is probably below 14.6 volts, so all the Silicon Controlled Rectifiers (SCR) in the regulator will be off letting the system voltage fluctuate.

Voltages were NOT stable - sub 30VAC - and bouncing.

I have grips, heated gear, and Solteks on this bike - but I've always been aware of voltages, and never really hammered it. During the SPANK last year, I ran heated gear and grips for several hours. The grips are Honda ST1300, and shut off when low voltages (sub 13.4, I think it is) are encountered. I never had a situation when the reading would not climb back up to 14.0 after I turned something on.

Once I have the stator out of the case a visual should give me more information.

 

[JamesK]

Awaiting further info with bated breath...

 

[ionbeam]

If this is an ElectroSport stator we will be treated to yet another set of pictures of a crispy critter. Carbonization rules! If this is a stock stator it will be an unusual event.

Assuming we have led K'dad on an accurate troubleshooting plan.

 

[JamesK]

I thought ElectroSport didn't make GenII stators?

 

[kaitsdad]

If this is an ElectroSport stator we will be treated to yet another set of pictures of a crispy critter. Carbonization rules! If this is a stock stator it will be an unusual event.
Assuming we have led K'dad on an accurate troubleshooting plan.

It's stock. I seem to recall someone on the forum with an 06 AE had to replace his not too long ago, but I can't find the post.

Considering the number of GenII bikes out there many of which have higher miles than mine, this really is unusual.

 

[Bustanut joker]

See what happens when ya get a good deal on sumpin? I knew that $98.00 deal was gonna getcha

Actually, that sucks for ya Hal. Yet another anomaly? Or is it, the shape of things to come...

:jester:

 

[kaitsdad]

Actually, that sucks for ya Hal. Yet another anomaly? Or is it, the shape of things to come...
:jester:

I sure hope not. At this point I'm willing to chalk it up to that small percentage of any assembly that has a flaw. Or maybe it's my hi-viz stitch. :blink:

 

[Silent]

Timely info, my X50 shows anywhere from 13.0-14.2 and moves around a lot also.

 

[madmike2]

Timely info, my X50 shows anywhere from 13.0-14.2 and moves around a lot also.

So does mine. In fact, because I'd get sub-12.0 meter readings I installed the Electrosport I've had in a box for 3 years before leaving for Canada.

It still fluctuates though not that low any longer.

I'm am electrically challenged when it comes to running diagnostic checks like Hal did and I had this brand new stator and gasket.

Before the issue, mine would run constant @ 14.2 volts. Those days are gone. And as Hal reported, on cool mornings commuting to work everything is normal, as before the problem started. Commuting home in the heat of the afternoon, stop-and-go traffic, the voltage will still drop to 13.8v, sometimes sown to 13.5v. If the cooling fan kicks on it will drop to 12.9v-13.2v.

Of course, I have no idea how accurate the X50 voltmeter function is. A datel would probably be a better choice. OR have the ability and knowledge to run more accurate tests like Hal did.

I think some of this started because of a bad battery. It wouldn't hold a charge on a local day ride and I had to bump start the bike 4 or 5 times during the day. I'm sure that didn't do the charging system any good. I replaced the battery but the fluctuations are still there. However, though the voltage readings jump around the bike never failed to start and didn't give me any problems on our CFR adventure.

 

[1FJR]

My Datal has been showing the same thing for awhile. It really fluctuates when the temps get up. Found that if I flash my FF50's the reading will hit 14.2 then stay there for awhile, but it will go down again. I have the Electroshort stator and I think that it is going bad after only about 20k I have run the bike with a second volt meter and it confirms what the Datal is showing me. I have not done any other diagonstic to confirm that, but will replace it anyway one of these days when I have some extra cash the stator will go back to stock and I will take pictures of the Electroshort.

Neal

 

[Silent]

Mine has yet to leave me walking, so for now, I'm just following along with intrest B)

 

[Fred W]

Guys,

You need to be a little careful about giving the voltage readout on your escort RD too much credibility. I have one too, and even when plugged into my car it gives me fluctuating readings. Fluctuating voltage on a mondo auto alternator is a pretty rare situation.

And while on the bike, when the Escort is saying the voltage is up and down, the Datel is saying all systems go.

 

[ionbeam]

Timely info, my X50 shows anywhere from 13.0-14.2 and moves around a lot also.

So does mine. In fact, because I'd get sub-12.0 meter readings

:nerdsmiley: Technobabble Warning :nerdsmiley:

If you don't want to know how the watch works, skip this post and don't waste your time.

We tend to think of DC voltage in our motorcycles as a straight line at 14.2 volts, and occasionally the straight line moves up and down a bit as displayed by your Datel/Escort/Fluke. In fact motorcycle electrical systems are quite 'dirty', containing lots of noise on top of the DC voltage. Many of you know this because of hum, buzz and static in your audio gear.

(This screen shot of my FJR's voltage was taken right off the battery post roughly 3 years ago.) In the following picture I have my sillyscope set to subtract the DC and only show the AC (noise) that is riding on top of the DC. Each vertical block is 1 volt, showing roughly 1.8 volts of noise. This picture is taken at idle, the noise voltage goes up slightly with rpms, the frequency follows rpms and the waves are a match for the number of pole pieces in the stator, with other elements matching the Fuel Injectors and the Coils.

An old fashion needle meeter will display your running motorcycle voltage with a fairly good degree of accuracy. If the needle meter is not damped or filtered take a very close look at the needle. You will see the needle 'buzzing' or very rapidly oscillating. This is caused by the AC riding on top of the DC voltage.

Digital displays work a bit differently than a needle meter. No mater what the brand, type or style of meter they all work like this: The meter takes a sample of the voltage; the voltage sample is sent to an Analog to Digital converter; the digital value is sent to a computer chip then to a display or directly to a display module. The digital display shows the output of the A/D converter. Now another sample is taken and the process repeats. On all digital meters the last digit (least significant digit) is rounded and therefore not exact like the other digits. This is why you often see meters called 3½ or 4½ digit meters. The ½ is in reference to the last digit being rounded.

Some differences between meters are how often they sample the voltage and how often they update the display. A professional meter like a Fluke samples the voltage thousands of times a second, then updates the display at least 4 times a second. The meter will perform the A/D conversion quickly enough that the display can flicker due to 'noise' with frequencys up to 5,000 Hz.

A Datel meter updates the display 2.5 times per second.

Some radar detectors display voltage also. This isn't because the manufacturer thinks it is a neat feature, the detector needs to know supply voltage in order to perform detection accurately. Same with the FJR ECU sampling the motorcycle voltage so it can fire the Fuel Injectors accurately. All bets are off on the sampling rate and display updates with radar detectors. If the RD samples voltage frequently and updates the display often, the RD will be prone to having flickering digits.

If your voltage meter happens to sample the voltage when there is a high noise spike it will display a higher reading, if it then by chance samples on a lower noise pulse the reading will be lower. As the meter happily samples along, sometimes hitting noise peaks and noise dips the display will flicker.

In automotive applications it makes sense to use some method to average the readings so that the meter display is stable, yet still responsive. As a technician you need to see the rapid display response to understand what a circuit is doing. On a motorcycle you only need to see a trend in what is going on. Automotive volt meters should average the readings so they only show voltage trend over several seconds. This is still plenty fast to see Bad Things yet stable enough to have a steady display.

The farther away from the battery posts the meter is connected, the larger the noise content will be, causing display flickering to be worse.

So, don't sweat display flickering, only follow the trend the meter shows. For automotive applications I would prefer a meter with only 1 decimal place of accuracy like 14.2 with no other digit to follow the 2.

The voltage trend that Hal was seeing is indeed reason to be alarmed and warned to fix it quick or be prepared to walk.

Fred, if you want to have some real fun sometime I can bring my digital O'scope over and we can take noise readings from several electrical systems. Gosh, I hope I can stand the excitement :lol:

 

[Fred W]

I have a Tektronix THS730A 200mhz digital realtime 1 GS/s handheld scope/multimeter right here next to my desk.

It's a pretty neat little unit. Not as fancy as the 4 channel, wide bandwidth, color display Tektronix digital storage scope in my car (forget model number and too lazy to look)



I should add that my Escort's voltage display fluctuation while in the car is not "flicker". It shows 14.1 V sometimes and at other times it is showing 12.X volts. I find it hard to believe that the actual voltage is varying that much so was chalking it up to the voltmeter being whacky. But it may be that where I tapped the power for the RD (from the rear view mirror maplights) is varying by some other means. There is something in the car that controls that power line to turn off the map lights if you forget them and leave them on.

 

[DaSpyda]

It's stock. I seem to recall someone on the forum with an 06 AE had to replace his not too long ago, but I can't find the post.
Considering the number of GenII bikes out there many of which have higher miles than mine, this really is unusual.

That was me

Basically, I ran driving lights all day through Texas and Kansas at 104-6 degrees on my way to Sturgis last August. I stopped to fuel in Nebraska and the bike wouldn't start. After a kind Nebraskan took the battery to his house for a charge, I disconnected the lights and didn't have an issue until the following spring at Daytona, where it totally failed.

I really believe the beginning of the end started on the Sturgis trip.