Alternator?

[Rev. Chuck]

Long story, aren't they all?? Anyway, mine starts with a battery, then a new battery that I (accidentally) fried, back to the old one, recharged.

 

I ride the the bike, (2005 R1200RT 75K+) and of late it at times just dies as the rpm lower, think final 10 feet costing to a stop light.. and won't start. Acts like a dead battery.

 

Well this exact scenario happened last week, in a parking lot. Got a new, good gel OEM battery, but since in the driving rain, jumped it, started right up, but failed to make it out of the parking lot. 20 min later the new batt installed, good to go.

 

The next day, rode to the same place, night riding and some high beam use, also a Gerbings jacket liner.. its cold here, and it died again!!! called a buddy, he came down with the trailer, off we go.. but it start right up.

 

So I pulled the Alternator, took it to a rebuild shop, he says can't get it to fail.. possibly the 'brush holder / regulator assembly' but not certain. looks good he says.. Can't get that part anywhere anyway.

 

I am super reluctent to buy a replacement with out knowledge thats it is the problem.. Any advise is most welcome.

 

Thanks any and all..

 

Rev. Chuck

[dirtrider]

Evening Rev. Chuck

 

Not really enough info to give you anything firm. It could be a battery issue, or could be an alternator issue, or could be that the alternator output isn't always getting to the battery due to a loose or broken wire, or it might be something else all together.

 

If your alternator shop can't get the alternator to fail then that doesn't totally eliminate the alternator but it sure points a finger is another direction.

 

That OLD Gel battery is a big suspect (especially if it dies as it comes to a stop ) as that is usually when the alternator output starts to fall off & the battery starts to take over.

 

I think I would have that old Gel battery load tested (a real load test not just a motorcycle shop hand held unit)

 

You might also be fighting something else-- like an intermittent open wire in the main harness (usually in the steering neck area)

 

My first suggestion to you is get a GOOD trustworthy volt meter on that bike/battery then see EXACTLY what is happening as you ride. (that should at least give you an indication IF your alternator is staying on-line or you battery voltage is suddenly falling off.

[Don_Eilenberger]

How did you fry the battery?

 

A local club member hooked his battery up backwards on his '07 R.. after the wiring harness was fixed (mostly around the alternator) it "seemed" OK - showed some charging going on.

 

Turns out it wasn't. He had problems like you did with the battery going dead - even brand new ones.

 

He had the alternator replaced. It then was fine.

 

But - the cause? Actually IMHO unknown, since it could have been a blown diode on the rectifier bridge in the alternator (the shop hopefully checked all of them..) or a loose/slipping belt. His had the first specification stretch belt on it, and it was original at around 40,000 miles.

 

BMW changed the specifications for the stretchy belt to a considerably shorter one - probably to eliminate slipping as the belts got older. Since he still had the original, in my opinion it's up in the air as to what the actual problem was. He got a new belt with the new alternator. So two factors that could have been the problem were replaced - making the actual cause unknown.

 

A blown diode will still let the alternator make volts, but not at a high enough amperage - so it limits the charging. A shorted diode will also limit the charging, and even worse, it will cause a significant current draw when the bike is off, discharging the battery. They can be tested with an Ohmmeter. Even a Harbor Freight $3/one.

 

Since you have 75k+ on your RT - can we assume you've done a belt replacement sometime in the near past? And did the alternator shop test the diodes?

 

Either one could be the cause, and I'd start with a new belt since it's a cheap part and has a periodic replacement interval.

[dirtrider]

Morning Rev. Chuck

 

We might also be barking up the wrong tree here-- I guess I should have mentioned in my above posting for you to verify that your brake servos are (always) shutting off when you release the brake pedal or hand lever. (your right foot isn't resting on the rear brake pedal due to a large cold weather boot is it?)

 

You might have to do this with the key-on but the engine off as it is difficult to hear the servos run with the engine running.

 

The brake servos draw a LOT of power & can run the battery down if they stay on even with the engine running unless the engine RPM's are kept high so alternator output is also high.

 

Without a voltmeter on your system to monitor (IF) your alternator is working through the entire ride & verify that your battery is not getting depleted as you ride then it is still a guessing game.

 

If you use a GPS powered from your bike's electrical system then you might have a handy voltmeter within that. Some GPS units have an external input voltage readout in one of the diagnostic pages that you can bring up by putting the GPS into diagnostic mode.

[TexasMule]

Speaking of voltmeters...does anyone recommend a decent (and decent looking) voltmeter for the R12RT? I've thought about putting one on my '08 but never really liked any of the cheaper ones I've looked at. Thought it might be a good idea to see how the alternator's doing and avoid the issue the OP is having. Nip a bad alternator/battery in the bud before she leaves me stranded.

[dirtrider]

Speaking of voltmeters...does anyone recommend a decent (and decent looking) voltmeter for the R12RT? I've thought about putting one on my '08 but never really liked any of the cheaper ones I've looked at. Thought it might be a good idea to see how the alternator's doing and avoid the issue the OP is having. Nip a bad alternator/battery in the bud before she leaves me stranded.

 

Morning TexasMule

 

There are many options if you don't have a radio as that removable panel (where the radio controls go) is a good mounting area. Just make sure whatever you use is waterproof.

 

On my old beater bike & my GS-A I use a product very similar to this one (a varying color LED). Battery Monitor -- One of EE friends built & tuned it's switchover voltage for me.

 

On my Ducati I also use a variable color LED (it m-i-g-h-t be from the company above (got it long ago) as it came from that country.

 

I did trade some E-Mails with the seller to have the light color vs voltage trigger points custom tuned for my Ducati battery voltage & alternator output voltage. It works great as that light shows up great at night & I have it mounted where it catches my eye if/when it changes color.

 

On my 1200Rt I use my GPS (if I ever need to monitor system voltage) as it has a supply voltage monitor screen. But for serious voltage work I have a small digital fluke with a ball mount that mounts to my GPS ball mount & simply plugs into my GPS power supply.

 

 

Battrey Monitor click here

[Rogerl]

I mounted one of these on the dash of my BMW R1200R. Look at the dimensions it is rather small but you can see the battery voltage at startup and riding to verify the alternator is working. The advantage of the size is it can be put anywhere.

 

http://www.aerostich.com/compact-digital-voltmeter.html

 

 

Roger L

[Guest Kakugo]

Speaking of voltmeters...does anyone recommend a decent (and decent looking) voltmeter for the R12RT? I've thought about putting one on my '08 but never really liked any of the cheaper ones I've looked at. Thought it might be a good idea to see how the alternator's doing and avoid the issue the OP is having. Nip a bad alternator/battery in the bud before she leaves me stranded.

 

There's a UK company called Datel which has a good reputation for its onboard voltmeters. Which are actually modified/rebranded/built under license/whatever Murata industrial volt monitors: good products, fully sealed (hence waterproof/dustproof) and shock resistant.

Mind they are not that easy to install without drilling your fairing... unless you get inventive.

That drilling part is what has been holding me back from buying one: knowing my drilling skills I'd end up with a very expensive mess.

 

[TexasMule]

Thanks guys, I can't decide if I want to actually see the # of volts or just a G/Y/R LED (pretty stealthy, and shows battery level while parked).

 

Thanks again.

[Rev. Chuck]

OK, so I removed all the plastic and the tank, cleaned up old suspect wiring..(dead lights and current gerbings) had the Alternator checked, replaced and new belt.. All worked fine and runs well… except… the brakes… I now have the brake system failure flashing light .. continuous …

 

Any thoughts of what I screwed up or forgot to re-do ??

[dirtrider]

OK, so I removed all the plastic and the tank, cleaned up old suspect wiring..(dead lights and current gerbings) had the Alternator checked, replaced and new belt.. All worked fine and runs well… except… the brakes… I now have the brake system failure flashing light .. continuous …

 

Any thoughts of what I screwed up or forgot to re-do ??

 

Afternoon Rev. Chuck

 

Did you ride the bike a short ways to see if the flashing light goes out? (if not then do that)

 

With key-on can you hear the brake servos running when you operate the brake pedal or hand lever? If not then did you hook the large red wire up to the back post on the alternator? That is the power wire that runs to the brake controller.

 

[Rev. Chuck]

AAAAHHHHHH……… I do not recall rehoming that wire!!

 

Oh I am so blessed with lessons..

 

 

[Dave_zoom_zoom]

AAAAHHHHHH……… I do not recall rehoming that wire!!

 

Oh I am so blessed with lessons..

 

 

 

Hi Rev.chuck

 

Well--------

That's our Dirtrider! Pretty good, eh?

 

Dave

[Rev. Chuck]

Very nice.. I still have the welt on my fore head… I hope this lesson is a one timer..

[Rev. Chuck]

Well, I did, replace the power wire to the brake system after all… Next idea suggestion?

[dirtrider]

Afternoon Rev. Chuck

 

 

Have you ridden the bike yet?

 

If so then your next move should probably be to use GS-911 (or dealer computer) to get the brake system failure codes.

 

Can you hear the servos come on as you work the pedal & hand lever with the key-on????? How about brake light working as you work the pedal & hand lever with key-on?????

[Rev. Chuck]

OK, so took the bike down again.. power was attached .. but what i did find was what appears to be a cap or tube missing from the ABS pump.. I don't know how to post a picture apparently.. but there are two small nipples one is capped, the other is uncapped. but shinny like it has been.. can't see a hose that would plug up.

 

Im headed to the store to buy a cap, thinking I may have knocked it off...

[dirtrider]

Evening Rev Chuck

 

[Rev. Chuck]

Blessings be on your bike Dirtrider!

 

I'll figure out this posting pictures soon.. But that was perfect, thank-You.. as was my thought. I replaced the missing cap, put the bike back together and fired it up.. Seems to be operating as normal.. Im teaching tomorrow so it will get tossed around a bit..

 

I am certain that there will more to the story… and were not even talking about my 500 set on the wall…