On the road - inconsistent voltage, help diagnosing please!
The bike should be sitting around 14 --> 14.3 V at all times while running, correct? And what is the resistance range for the coils of the generator. Manual says 1 OHM max, but what is the min value?
And the full story:
So, turns out I'm getting some REALLY erratic charging behavior, and I'm suspecting this is not normal.
This is the first ride I've done with a voltmeter mounted, but it just doesn't seem right.
Currently at a friends garage for a few days, and have begun doing some testing with the multimeter, but have some questions for you on specs, where the manual fails to give the info.
First off, a diagnosis. It all started when I probably made a major mess up and accidentally shorted the two wires on the starter relay pre-trip. During the ride, my voltage was all over the place, but basically it breaks down like this:
With the battery at a full charge, IE: 12.7 V, and I key on, voltage comes down to about 12.2 V.
I start her up, and it comes to around 13V.
If I let it idle, with only the low beam and my GPS and voltmeter powered on, it will OCCASIONALLY come to 14V, and sit there.
Any application of throttle drops my voltage down to anywhere between 13.1 V --> 13.4 V. If I roll off the throttle, it will occasionally climb back to 14V but will NEVER see more.
If the fan comes on at idle, voltage immediately drops down to 12.7 V.
Being on the road, I haven't had the heart to let it sit like this and see if the voltage continues to drop as the battery drains. I've always either turned the bike off to cool, or taken off down the road to push the voltage back to the 13.1-->13.4 range.
So first things first, I needed to confirm my findings with an accurate meter.
Yep, at 5000 RPM's, the reading at battery is only 13.35V, not the 14-15 the manual states it should.
All connections looked good, so on to the generator.
None of the three coils are grounded to the engine case, so that's good.
Next the resistance test.. well here's my main question for you:
What is the lowest acceptable resistance one should find between generator coils?
I've been following this flowchart found HERE, keeping in mind its generic, and cross-referencing every figure with what I could find in the manual. Interestingly enough, the manual only states a max resistance of 1 OHM, whereas the generic chart states a grange of .5 --> 2 OHMs.
All of my coils are returning a value of .2 --> .3 OHM. Is this normal?
Other than this, the generator passes the AC output test, with all 3 readings across coils outputting around 62 VAC. (Based off of the chart, stating I should be looking for even #'s > 50 VAC. No actual figure for this in the manual that I could find.)
I'm about to move onto the RR now, and do some tests on the diodes, but before I do, I wanted to make sure that my generator is in fact still good. Seems that way, but just wanted to confirm my resistance was in spec.
Right now, it's looking more and more like I toasted the RR when I crossed those two wires (twice actually.)
Does this seem possible?
One last question for you gurus... are my voltage figures accurate at 13.1 - 13.4 V while riding, or should this baby be putting out a solid 14 --> 14.3 V at all times, like every other bike I've owned?
Thanks!!!! Your prompt help is so greatly appreciated! Hopefully this little issue will help teach some others about our charging systems as well, since I couldn't find any solid figures via search.
Well now I am truly puzzled.
I was "hoping" to find a bad diode in the RR. Turns out they're all good... Top and Bottom diodes all check out in both directions.
So could it really be the RR?
If I'm correct, checking the diodes is the equivalent of checking the Rectifier part, so perhaps it's the Regulator part that has gone bad? In my googling last night, I think I read somewhere that it was possible to test this portion, but apparently it's pretty complex, so no directions were available.
Anyone know how, or should I just spring for a new Rick's Motorsport RR now hoping this will solve my problems.
I think at this point, all that is left to do is to check relays and the other diodes on the bike, but I'm not so sure they pertain to my issues?? Seems like they mainly control the start / kill functions of the bike. No problems there.
Any thoughts before I drop $150 + overnight shipping in 1.5 hours??
Does anyone out there have the info on the min OHM of the generator coils, or the expected VAC at a specific RPM? Can't believe KTM doesn't have this info listed.
i don't see things that bad, altough i can see that battery is not that good, what is teh voltage on the batery when cranking the engine? i bet is somewhere around 10 volts
Resting voltage 12.7 V (75% charge?), Lowest voltage 9.5V, and highest voltage after letting it sit for a few minutes, and then reving up to 8K, only 13.7V.
Yes, the battery probably took a major hit in its life when I shorted the two wires.. it was brand new before that, a month and a half out of the box, with only about 2 weeks worth of use and a life on the tender.
Perhaps a new battery would solve some of the starting issues I had, and yes, it does seem that it is getting a full charge from the system (maintaing its 12.7V) but what about these inconsistent voltage readings while riding. This is what really concerns me. A system the drops to 12.7V when the fan runs?? Doesn't seem right. At all.
A couple times on my trip it didn't quite have the juice to start.
First one was out of nowhere. Was riding along on the interstate just fine.
Stopped for gas, bike wouldn't start. Rolled it away from the pump. Tried again, and it started. Went to ride it, gave it some throttle, and it died off, threw a FI light etc. Basically too low of a voltage it seemed to me at the time.
Let it rest again, paid careful attention to let the ECU finish it's startup cycle before hitting the button. It started and off I went. During this rest period I did some tests, and the battery was registering in fine at that 12.7 V.
Later in the day I got brave again and went to tackle some trails. Fell over, did my thing. But basically the bike was warm and fan got some use. Got to the end of the trail, but there was a good bit of start / stop along the route. Turned off the bike at the end to rest. Tried to start again after a careful wait period of ECU boot. No bueno. Turned off bike, waited again, tried again and it started fine.
Hmmm, maybe I should check those starter relays after all....
EDIT: After letting the bike run for a bit to test how low the battery would drop during start, I just walked back out and looked at the meter, looks like it is sitting at 13.03 V right now.
Well, now I'm a little more confused than before.
Bolted everything back together and took the bike for a little spin.
Seems to be sitting at 14.1V now @ idle.
Same issue under throttle, voltage drops, but only to around 13.4V minimum this time.
Heres where it gets new.
At idle, when the fan comes on, voltage will only drop now to 13.7V (as opposed to 12.7V)... but ONLY if the brake lever is pulled. If I release, the fan will now run, and bike will idle fine at 14.1V.
So what on earth is going on here?
What accessories do you have on your bike? list them
it's a 990 so it always have the lights running, correct?
What brand of battery and model do you have there?
Any charger at hand? (if so, what amps does it puts out?
(do you have whatsapp messenger or Blackberry messenger? so i can help you out chating)
Actually, with that most recent test ride, the headlight was pulled.
It's a DEKA battery, AGM in standard size.
I do have a charger here, it's a Die Hard charger... says automatic with a switch for low main or maint-free batteries and it can output 2A, 10A, and 50A
As far as accessories... I have an Eastern Beaver PC-8 fuseblock connected to the positive post near the starter relay. It's got 2 pos lines that run off, unswitched 20A, switched 30A. Connected to this, not much. 10A Unswitched SAE connector (unconnected). 5A GPS mount switched, and 2A voltmeter switched.
Downloading the WhatsApp messenger right now. Will shoot you a PM with my username once I get it setup.
Thanks so much!
This is the best resource I know of for issues like this:
GZERO helped me out a bit by phone, and made me realize just how crucial battery life is on these newer FI bikes.
Took a close look at the battery tonight, and it turns out its a Deka ETX9 (A Yusa YTX9-BS Equiv.) nowhere close to the stock YTZ14S.
Maybe I'm off here, as in the "Alternative Battery" thread, I notice some people are running a Batteries Plus equivalent to this ETX9... but I suspect that this battery is just too underpowered.
Think I'll be heading out tomorrow to grab a new battery. The question then, which one. Do I drop the $180 on the stock Yusa, or go the LiFePo route? Or do the cheap $90 Batteries Plus equiv. Choices.. choices.
Hope this solves the problem though.
DO check your VR.
I once had the "starting issues" you describe and automatically assumed it was a bad battery (cheap Chinese sealed battery than came with the bike from the P.O). I bought a new battery to replace it but it turned out that Chinese battery I took out was not being charged properly, but was still good and gave me about one more year of service (I found this later).
At the moment, I installed a brand new Yuasa and it lasted two days because the VR was bad and fried the battery. The voltage readings I got fluctuated a lot, so it was not easy to diagnose... it would sometimes behave normally (for an extended period of time), it would sometimes go around 11.7v (which is the reason for the Chinese battery not being charged and thus not being able to start the bike on some occasions)... and then, sadly, the voltage went above 16v which happened when I installed the expensive Yuasa (voltage reading which I realized only after the battery was already damaged).
Havent found any info on how to test the regulator portion yet though.
I don't see a problem with your charging system.
At idle, the bikes stator (and your AC test confirm it's working fine) is not putting out a lot of power. Also, the fan and lights use a lot of power. So seeing 12.7 at idle with the fan on would not worry me. I am guessing you just started the bike and let it idle to warm up. In this case, it's had very little time to bring up the battery to a fuel charge. If you road the bike around for 10 minutes, then you would see a higher voltage and the fan turning on would make less of an impact.
And as long as the charging system gets into the mid 13V at cruising speed, then I would also not worry. 14V is nice, but can overcharge a battery if it stays at that voltage for too long. But AGM batteries like a higher voltage.
The best way to charge any led acid battery is to bring it up to 14.2V at the recommended charge rate of. Then float them at 13.5V. So ones the regulator sees 14 or so volts, it may kick down into float mode and drop the voltage down.
The rectifier/regulator on a motorcycle has a lot to do and can control very little. It can't control the amount of power coming from the stator like in a car alternator. At idle, the amount of power coming from the stator may be just over the amount needed to run the bike, leaving little for battery charging. But at 5,000 RPM, the stator is making way too much power and the regulator has to burn it up as heat.
As fast as the 9x0 revs, the regulator can have a tough time keeping up. But it does not really have to as batteries are very forgiving of voltage/amps spikes.
I have a volt meter on my 950 and the voltage has always been all over the place, but it's in the 13V range when cruising and that is all that really matters. I got 6 years out of the stock battery. But I do keep it on a trickle charger when I leave it parked for more then a week.
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