Post by: Kchop on July 25, 2024, 12:15:54 PM
I have a 1993 k75s. Low miles, battery about a year old. Did a 600 mile ride 5 months ago, no problems.
A week ago I'm coming back in from a ride and bike dies suddenly while riding. Turn the ignition switch to second position , don't hear the fuel pump...before I panic I look at the fuse for the heck of it, its blown. I replace (feeling good about myself) more riding.
Yesterday I ride to store (couple of miles) turn bike off, coming back out battery totally dead. I have someone run me out a portable charger, JNC 660. Put it on the terminals and with the kill switch in OFF position AND the
Ignition switch in absolute OFF position, bike is trying to start?? Is that normal??l (never used the portable charger before). I turn key to "on" position, kill switch to run..bike starts . Remove neg terminal clamp , bike dies.
Was thinking alternator...now not so sure.
Any help appreciated,
Thank you
Post by: Ingo on July 25, 2024, 01:45:09 PM
Post by: Kchop on July 25, 2024, 04:36:15 PM
Post by: Chaos on July 25, 2024, 10:10:35 PM
Post by: Kchop on July 26, 2024, 10:10:12 AM
Couple of questions: trying to hunt down video on alternator replacement for this model?
I see replacement alternators with wide range of prices. Anyone have suggestions for best part supplier? If there's a better forum for that question please let me know.
Thanks
Post by: Laitch on July 26, 2024, 10:41:12 AM
Anyone have suggestions for best part supplier? If there's a better forum for that question please let me know.Euro Motoelectrics (https://www.euromotoelectrics.com/category-s/1770.htm).
Post by: Martin on July 26, 2024, 04:47:23 PM
Regards Martin.
Post by: Kchop on July 26, 2024, 05:10:58 PM
Sorry for the basic questions, just starting to work on bike by myself.
Post by: Kchop on July 26, 2024, 05:23:13 PM
Post by: Ingo on July 26, 2024, 05:34:12 PM
In fact, there's a write-up from yours truly on exactly this...
Post by: Ingo on July 26, 2024, 05:55:49 PM
https://www.motobrick.com/index.php?topic=15675.msg139156#msg139156
Post by: Kchop on July 26, 2024, 06:54:38 PM
One more thing. Trying to find out before I dive in whether its a 32 A or 50A alternator. Bike is a 93, but running a VIN check, its manufactured in 92. Of course early 93 is 32A, later 93 is 50A. Any insight there?
Post by: Laitch on July 26, 2024, 07:18:16 PM
32 Amp
(https://www.motobrick.com/gallery/4/1601-260724191022.png)
50 Amp
(https://www.motobrick.com/gallery/4/1601-260724190816.png)
Post by: Laitch on July 26, 2024, 07:23:43 PM
new brushes are 10mm in length, brushes due for replacement are ≤5mm in length.
Post by: Kchop on July 27, 2024, 02:12:24 PM
Took a voltmeter, set at 20:
Battery 12.41 no key in ignition
Battery 11.87 Key in on position / no start
Battery 11.69 on initial start / Charge light on
Battery 12.32 rev to 1500rpm/ charge light goes off
Battery 13.27 @ 2000 rpm
Shall I interpret this as the alternator doing its job? Could it just be a bad battery that's only a year old??
Post by: Ingo on July 27, 2024, 03:19:55 PM
Seems to me that you're not getting proper voltage.
Let some more people chime in here...
Post by: frankenduck on July 27, 2024, 03:39:43 PM
(https://i.ebayimg.com/images/g/PnAAAOSwp8BjgpZu/s-l1600.webp)
Post by: Kchop on July 27, 2024, 04:29:06 PM
Post by: Ingo on July 27, 2024, 06:58:24 PM
Post by: Laitch on July 27, 2024, 07:13:09 PM
ok, thank you for the test suggestion.If your battery was charged overnight with a slow charger and only tested at 12.4V, that is not an optimal result. Try it again to see what you get.
Took a voltmeter, set at 20:
Battery 12.41 no key in ignition
Shall I interpret this as the alternator doing its job? Could it just be a bad battery that's only a year old??
Which amperage is your alternator? The 32A's regulator is easily removed so you can measure the brushes. You need to remove 50A's rear cover to access it.
Post by: Kchop on July 27, 2024, 07:25:25 PM
I'll try agin tonight.
32A Alternator. I'll remove and look at the brushes and do what Ingo says, cuz that part won't hurt that much....
Post by: Kchop on July 27, 2024, 07:29:18 PM
Post by: frankenduck on July 27, 2024, 07:48:43 PM
https://www.amazon.com/gp/product/B07G8GHCFG
"Half" battery:
https://www.amazon.com/gp/product/B074VFKRKL
Post by: Kchop on July 28, 2024, 11:07:37 AM
Battery: 12.59 this morning with absolutely no load.
Post by: Kchop on July 29, 2024, 10:03:54 AM
Thanks
Post by: The Mighty Gryphon on July 29, 2024, 10:15:31 AM
What matters is what a load test shows. You can have that done at the local auto parts shop.
What is the charging rate of your charger? The brick battery is fully charged with 19-21 amp hours. If you are trying to charge a dead battery with a 50ma "trickle charger it will take approximately 240 hours to get a usable charge if it will charge the battery at all.
Post by: Kchop on August 03, 2024, 02:08:58 PM
So installed a new voltage regulator. Same result.
No load on battery 12.41
Max Voltage at 2000 rpm 13.35
To answer Gryphon: Tried 1a charger as well as 5A charger. So, even though 1a charger was on roughly 16 hours, and registered full charge (Green), are you saying this might not be enough for full charge on battery?? Also, wouldn't battery charge to full if driving a couple of hours??
Ingo: when are registering 14.4 V . When bike on and running??
Thanks
Post by: daveson on August 03, 2024, 04:54:05 PM
The battery still isn't fully charged and it's not very old. If your bike sits around for long periods without being used, it might help to charge it with a smart charger.
There might be an unwanted drain on your battery. You say the bike stopped, then you replaced a blown fuse which got you going again. Which fuse blew?
Post by: Ingo on August 03, 2024, 11:14:12 PM
The "charge light" is on right after start and goes out once rpms go past 1k to 1200 or 1300 rpms and then stays out.
You might have a bad alternator that ALSO caused your battery to go down the tubes....
I find batteries to be a pain, always going bad, I finally sprung for a lithium, consistently on its special charger in the garage when parked.
Post by: Kchop on October 22, 2024, 12:11:15 PM
Revisiting this problem: So, I have replaced the voltage regulator, (was told by BMW shop that the brushes on the old one were fine)
I replaced battery, (even though apparently old one was fine) Failed at one auto shop, passed at another..Finally brought it into BMW Moto shop, mechanic ran two tests from two different testers, said it was good battery. 32W alternator outputting about 13.7 at 2500rpm or so.
Bought Battery tender voltage gauge. so, am I. missing something?? Can alternator be "half-broken"? Going to drive around with voltage meter taped to gas tank (advice from shop) to see if it stops charging. Anything else that would affect battery depletion?? I've heard of something called a "parasitic draw"? anyone can comment? Also heard it doesn't usually affect k75's.
Thanks in advance.
Post by: Kaos on October 22, 2024, 12:58:31 PM
Battery depletion on a k is pretty hard when the bike is driven. Tends to only happen when your carge indicator (blue wire from the alternator isnt connected to a warning light, or faulty wiring, faulty bulb you name it.
How often do you blow a fuse, is Everything stock and what are the current issues after replacing the components and i what conditions?
Post by: frankenduck on October 22, 2024, 04:30:33 PM
Post by: Kchop on October 22, 2024, 04:36:38 PM
Post by: Kchop on October 22, 2024, 04:38:34 PM
Post by: Laitch on October 22, 2024, 05:43:55 PM
So, interesting. I have a aftermarket fuel pump. It has a 7.5 fuse. . . . BMW tech suggested I replace that with a 10.:nono2:
Post by: Kaos on October 23, 2024, 05:09:37 AM
But not having issue solved with battery and voltage regulator replaced and the alternator checked by BMW, there are still several other possibilities, like bad grounds that can lead to the battery to charge inefficient or badly.
or A faulty starter relay - which adds up to your bike starting when charging earlier mentioned in the post, and is in my opion worth looking at or even replacing it.
When its stuck in "on" position it will contuesly allow for power draw.
On top of that, one thing caugt my attention and that is the fuelpump. It blew your fuse and was solved by a higher amp fuse thus meaning its using more power than a standard fuelpump, in combination with either of the above or- just the charging capacity while riding on a later model k75 (which i am not too fermilliar with) could cause your bike to use more power than the bike is able to charge back into the battery.
As far as i am aware K-bikes charges the bike sufficiently to basically not having to charge your bike for several months if even not at all when driven on the regular.
Post by: Laitch on October 23, 2024, 08:25:48 AM
. . .one thing caugt my attention and that is the fuelpump. It blew your fuse and was solved by a higher amp fuse thus meaning its using more power than a standard fuelpump, in combination with either of the above or- just the charging capacity while riding on a later model k75 (which i am not too fermilliar with) could cause your bike to use more power than the bike is able to charge back into the battery.He appears to have replaced it with a 7.5A fuse and it has worked ever since. The BMW tech recommend that he replace it with a 10A. Maybe Kchop will verify that.
The original equipment fuses with exposed filaments degrade over the years and eventually break. Replacing them with fuses with sealed filaments is good strategy.
Post by: Kaos on October 23, 2024, 09:44:37 AM
He appears to have replaced it with a 7.5A fuse and it has worked ever since. The BMW tech recommend that he replace it with a 10A. Maybe Kchop will verify that.
Yeah that is tad bit unclear to me if it's either a 7.5 or a 10amp fuse. But if its a 10, its worth looking into.
Post by: Laitch on October 23, 2024, 05:52:37 PM
Yeah that is tad bit unclear to me if it's either a 7.5 or a 10amp fuse. But if its a 10, its worth looking into.When did it become okay to substitute a higher amperage fuse for a lower one? Is that a Kaos standard or what? :laughing4-giggles:
Post by: frankenduck on October 23, 2024, 06:14:01 PM
Post by: frankenduck on October 23, 2024, 06:14:18 PM
Post by: Laitch on October 23, 2024, 10:51:41 PM
Post by: Kaos on October 24, 2024, 12:03:12 AM
When did it become okay to substitute a higher amperage fuse for a lower one? Is that a Kaos standard or what? :laughing4-giggles:
Hold on, how did it become a "me" thing? :laughing1:
If kchop did actually replaced the fuse with a higher amperage fuse (which he has to confirm) , the possibility is that he is depleting his battery because of the higher amperage usage of his fuel pump. So if he has its worth looking into the power usage of the fuel pump vs the charging capacity of the bike.
And not replace his fuse with a higher one if he hasnt because that will not fix the problem. Even if his fuse keeps blowing.
And also dont forget the grounds and (in my opinion worth doing in the whole matter) replace the starter relay
Post by: Laitch on October 24, 2024, 10:18:26 AM
Post by: Kchop on October 24, 2024, 10:53:26 AM
he thought I was trying to sell him something, hoisting that bike into van with a narrow ramp, etc.
To clarify: I have not yet replaced the 7.5 fuse with a 10. To replace was suggested by BMW Moto mechanic. The fuse blew only once after like an hour long ride. After that it seems to be fine.
According to manual, the proper fuse for that fuel pump is 7.5A.
Is there a proper way to test the starter relay? In reference to the alertnator, it either works or doesn't correct?? Has anyone experienced an alternator malfunctioning when it bike is ridden for longer rides? After bike is"hot'?
Post by: Kchop on October 24, 2024, 10:59:30 AM
Also, unless I'm misreading..a broken or "stuck" starter relay would result in the bike trying to start even while it is already running, correct?
Post by: Laitch on October 24, 2024, 01:30:23 PM
:laughing4-giggles:
Post by: daveson on October 24, 2024, 05:55:46 PM
Post by: Laitch on October 24, 2024, 07:46:53 PM
Post by: daveson on October 24, 2024, 10:19:08 PM
Post by: daveson on October 24, 2024, 10:39:08 PM
I would hope a new battery wouldn't get that sad within two years. There might be a parasitic drain on the system. One simple and easy test is to check for a drain with the ignition off, using a multimeter. Set it to 20 volts, DC. Remove the battery negative lead from the battery negative post. Set the multimeter negative probe on the battery negative post, and the multimeter positive probe on the battery negative lead. It should read about 12 volts, this shows a drain on the battery, the clock, as shown in the photo. Now remove fuse three, which supplies power for the clock. The multimeter should now read zero volts, if it reads about 12 volts, there's a drain on the system.
Watchyagot?
IMG_20241023_120015.jpg (62.77 kB . 768x576 - viewed 315 times)
Post by: Kaos on October 25, 2024, 01:46:29 AM
But this does raise more questions. Because the amperage usage is quite constant from a fuel pump, which makes me question why it doesnt blow earlier in the ride. And one of the things i can think of that happens about an hour into the ride is the fan kicking in. Were there any electrical fixes done to the bike in the past?
Still I think your aftermarket pump uses more e-juice than it should.
My personal preference, and some may not agree, is to replace the [cheap] component that failed me once (being the relay.
Post by: Laitch on October 25, 2024, 11:53:29 AM
We as, I guess, a collective just want to ride out and not end up stranding in the middle of nowhere. Then this would have been an Aprilia forum.:laughing4-giggles:
Post by: Kchop on October 25, 2024, 03:07:24 PM
Yes, fuse 6. Gotta drive around my neighborhood like a madman for a while.....
No electrical fixes ... It's been pretty steady.
Post by: Kchop on November 04, 2024, 02:29:52 PM
Did as @Daveson suggested: meter>neg probe on neg terminal, pos probe on neg lead. Pulled fuse 3 and I get 0.21 read out.
Hooked up battery tender voltage readout to battery and taped leads to gas tank (keep in mind new battery and voltage regulator) never even got close to 13.7 at 2500rpm (like previously) Drove around for about an hour , pulled into garage , kept motor running and came out about 15 minutes later and bike was off and battery totally dead on restart attempt.
SO, I gotta think alternator at this point , NO?
Post by: Kaos on November 04, 2024, 04:08:26 PM
Maybe.
What i noticed reading back to the origin is, no-one has asked what your charge indicator does.
Do you have a charge indicator and what does it do (read in arny's voice)
When you left it running was it idling low rpm with all electrics on?
Somewhere along the line I still think its a combination of things.
Like usage vs charing.
Or not charging because your charge Indicator is faulty.
Could also be the alternator yes.
and for double checking, you have a 12v 40AH batt right? and does it freeze like minus 40 in your garage?
Post by: frankenduck on November 04, 2024, 04:32:46 PM
Post by: frankenduck on November 04, 2024, 04:33:28 PM