The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: GrimReaper on December 12, 2009, 12:53:20 AM
-
the voltmeter shows that the alternator charge the system only in high RPM.in around 4k rpm it shows 14 volts,but when idling only 8-9 and after a 20-30 seconds engine died.I opened the alternator and check the brushes(looks OK)I spoke with the local dealer and they told me that the alternator is pretty reliable and usualy the diode board or some other relay is the reason for that.I hope someone can help me with this problem.
Best GR
-
8 or 9 volts at idle is not right at all and maybe low enough not to provide a decent spark which is maybe why the engine died. What state is the battery in? Voltage tests of the charging system are only really valid if you start with a good battery that is fully charged. Also is the charging light illuminated with the ignition on and before you start the engine ? If the bulb has failed there will be no current flow to the alternator field windings which can result in the symtoms you descibe i.e. no charge until the engine is at high revs. Best to check the basics first before assuming you have a problem with the diode board.
-
I agree with Barry, check to see if the 'GEN' comes on when you turn the key to the run position .
If it doesn't, you need to do a bit of simple troubleshooting .
If the "GEN' light doesn't come on, here's the troubleshooting steps .
First, remove the positive lead from the battery, and secure it so it doesn't spring back and touch the positive terminal of the battery .
The reason for this, is that there are 'hot' terminals under the front engine cover, they have power to them regardless if the ignition switch is in the off position or not .
You can damage the diode board if the cover touches one of these hot terminals .
Remove the front cover from the engine .
Reconnect the positive lead to the battery .
Place a wire, or other metal object between the slip rings on the alternator rotor, with the ignition switch in the on position, the light should come on .
This checks the wiring and the bulb, if it's good, this test is done .
If the light doesn't come on, you need to open the back of the tachometer, and check the bulb to see if it is good, or just maybe loose in it's socket or possibly the wiring or bulb socket is faulty .
If the bulb is at fault, it's a common SAE 168, 194 type bulb, available from an auto parts store, get the incandescent type bulb, not an LED type, the LED bulb will not pass enough current to properly operate the charging system .
If the test for the bulb circuit checks good, you need to check the alternator rotor for continuity of the windings .
Turn the ignition key to the off position, or remove the positive battery cable again .
Place small pieces of paper between the brushes and the slip rings, place the leads from the multimeter on each of the rotor slip rings, you should get around 2.8 ohms .
If you get infinite resistance, the rotor is bad .
-
Bob, that's an excellent, well written and easy to understand diagnostic. [smiley=thumbup.gif]
In my opinion, this thread should be considered as an addition to the FAQs Section; after all input from the R65 crew has been received.
Both my R65s have a Generator Light Auxillary Circuit that keeps the charging system doing its job if the GEN bulb fails. Mandatory on the '81 as the actual light and instrumentation was replaced with the digital TrailTech product. Rick Jones has a kit or you can roll your own as I've done on the '83 Mexico Bike.
http://www.motoelekt.com/genlightacc.htm
Monte
-
Only thing I didn't like about the Motorrad Elektrik kit, was the type of connectors that are provided .
They cut the insulation of the wire, I personally didn't use them .
-
I bet the battery is bad and there is nothing wrong with your charging system. Check out the battery first.
-
the Gen light iluminated with ignition on and when the bike runs on rpm above 2k comes off.When idling iluminate again and after while the engine dies.
If the charging system works then i think it does matter how good is the battery.The alternator should provide ehough voltage to charge the battery and to keep bike runnin,
Bob i will run the test for the rotor tonight.The gen light seems to be OK.
-
Sounds like a normal Bosch charging system to me. Really. With my Omega 400 watt system the light doesn't go out till about 2700 RPMs. It comes back on on the way back to idle at about 1700 RPM. At idle the battery is the only thing powering the electrical system with the Bosch Alternator.
I would check the battery and all the connections that connect the battery to the frame (ground) and the rest of the electrical system. I think the positive lead runs up under the top cover to the starter solinoid. Make sure these connections and the battery connections are goodntight.
If your system is putting out 14 volts at speed then your charging system is probably AOK.
-
If the light comes on, with the switch in the run position, and goes out like Bill has said, doesn't sound like the charging system is at fault .
Battery is a likely suspect now .
Is your battery a sealed type, or can you add distilled water to it ?
If it is a serviceable type, remove the caps, and see if the plates are exposed .
Like Las Vegas, the Phoenix heat is pretty tough on batteries .
I've gone to sealed AGM type batteries on the bikes .
-
Battery is low for sure,but Bob isn,t the alternator suppose to provide enough volts and sparks to keep the bike runnin even when idling,or maybe not because the bike is not desined to idle for a long term?
-
No. Not on the Bosch system. The GEN light is on which means the battery and the battery alone is powering the system.
Now if you had the Enduralast Alternator system...maybe?
-
Unfortunately, this charging system doesn't start producing more power than the bike is consuming, below the 2500-3000 rpm area .
If you ride in a lot of 'city' type riding, the battery will get discharged .
When I lived in Chicago, when the weather was conducive to riding, if I took the bike to work, I had 5.5 miles and 13 stop lights, if I didn't charge the battery on my weekend, or take the bike out for a good highway speed ride, the battery would be discharged enough in 7 workdays, that the battery wouldn't operate the starter .
A float charger connected to the battery when the bike is not in regular use, or your riding style is mostly city traffic, is probably a good idea .
-
Yes i ride the bike only in the city for a 5-6 miles a day with a lot of traffic lights.Sounds exactly like what happened to me.I will start with recharging battery first
-
If you need to replace the battery, I don't know what kind of sources you have for batteries, but the R65 takes a non-standard battery size .
Three of us here have installed a generic AGM type battery .
www.staabbattery.com/product/UB12220-v.html
Don't know what kind of service life to expect, but the price was quite reasonable .
-
Batteries tend to get taken for granted. Like Bob I have a short commute to work that takes 10 or 12 mins. How much charge is a battery going to get in 10 mins especially in the winter with brake lights and indicators and headlights on the go all the time. The answer is none in fact it will discharge. Even in the summer it will get no more than if you put it on charge in the garage for 10mins which amounts to next to nothing. Riding a bike does not charge the battery faster than a normal garage charger. If it did it would damage the battery.
Use of a battery tender or regular charging is not being fussy its essential unless the bike gets regular long runs and I mean long runs like hours.
-
All my bikes come home and get hooked up to a Batterytender every time. Makes the batteries last longer.
http://www.batterymart.com/merchant2/merchant.mvc?Screen=CTGY&Store_Code=BM&Category_Code=deltran-battery-tender-battery-chargers&SortBy=&show=48&pl=&ph=&char=
My R65 has a Odessy PC680 in it and as such it gets the big charger.
http://www.batterymart.com/p-battery-tender-plus-12v-5a-wp-battery-charger.html
If you get the AGM battery then you really need the bigger charger. I had a regular 1.25 Battery tender let my Pc680 get discharged!!!!
(Love the Pink battery Tender. Just in time for Christmas...)
Good Luck,
-
The battery is YUASA not a sealed type. should i open the six caps before charging
-
Not really essential providing there is a vent tube which is the normal arrangement. You might want to remove them to check if a top up of water is required.
-
How long has that battery been in there? If it's more than a year then its probably time for a new battery. But here is the drill....
Not necessary to put the caps off to charge. I would pull the battery out of the bike and charge on the bench though. When they get cooking the make a lot of gas. Kind of caustic to the metal parts on you bike.
Make sure each cell is filled to the bottom line with fluid.
If you need to add water to a cell make sure it is distilled (steam Iron) water. Never use tap water.
Charge the battery on slow overnight (if it is a multi level charger).
When done check each cell with a specific gravity tester. (Little eyedropper thing with little balls inside). This will tell you how strong each cell is. Get one from Autozone or Napa. When a cell is good all the balls will float (I think - its been a while). If even one cell is bad, throw the battery away and get an expensive but really long lasting AGM battery - Odessy PC680 highly recommended.
If the cells check out. Make sure each cell is now at the Full line (top up with distilled water) and put it back in the bike.
On a Deltran Battery Tender you need to check the fluid level every six months as the cells will "dry out".
Good luck.
-
Since I moved to the Phoenix area a little over 16 years ago, my commute is now 11 miles, 2 miles surface streets, 9 miles urban expressway, I haven't had any charging issues, until I added two PIAA 40 driving lights (55watts each) .
I put a charger on it Friday night, for about 6 hours before I use the R65 on the weekends for work .
The additional electrical load of the two PIAA 40 driving lights, is enough to cause problems, if I use them while in city traffic .
Here in the oppressive desert heat of the southwestern US, I would check the fluid level on the battery about once a month, until you see how fast it loses water .
I forgot about checking specific gravity of each cell, it's been 10 years since I've had a serviceable type battery !!!!!!
If the battery doesn't have a vent tube on it, install one, the metal seat pan will get eaten up by the gas discharge from the battery .
-
Only thing I didn't like about the Motorrad Elektrik kit, was the type of connectors that are provided .
They cut the insulation of the wire, I personally didn't use them .
I dumped 'em, too. Used the "proper" technique.
I run Staab generic AGM that fit both R65's battery box perfectly.
Monte
-
the battery is about 5 months old.For last month i ride the bike about a 5-6 miles a day in the city so i guess with all the traffic lights and stops it is not enough to keep the battery charged.i will try to ride tomorrow with recharged battery,if the problem occurs again will test the rotor.
-
Well it looks like the voltage regulator is faulty.I recharge the battery and after a ride(about 40miles) i had the same problem.So i check the regulator.I followed the instructions from this site:
http://bmwmotorcycletech.info/testingvoltageregulators.htm
and the results are:
With voltage regulator the voltmeter shows 13.1
Without shows over 14
I ordered a new one -Borg Warner R588
Will post results as soon as i recieve it
-
Was 13.1 your resting battery voltage? Simple fix anyway.
-
Was 13.1 your resting battery voltage? Simple fix anyway.
13.1 around 4k rpm
-
Turn the ignition key to the off position, or remove the positive battery cable again .
Place small pieces of paper between the brushes and the slip rings, place the leads from the multimeter on each of the rotor slip rings, you should get around 2.8 ohms .
If you get infinite resistance, the rotor is bad .
Just ran that test and the multimeter reads 0 ohms resistance.Is this means that the rotor is bad?
-
Rick Jones at Motorrad Elektrik offers a remanufactured rotor $90.00 (or $124.95 for a new rotor).
Send your dead one as a core exchange. Monte
http://www.motoelekt.com/charging.htm
-
Sounds like the rotor has 'shorted' internally .
Not too uncommon, to have the insulation on the windings, which doesn't amount to much more than a coat of thin, varnish like material .
That coupled with the centrifugal forces try to move the wires around, along with age, and heat exposure breaks down the insulation, and then bare wires touching each other .
-
I will order a new rotor from Rick tomorrow.The problem is i don't have a repair manual :-[.Can u guys give me some advices how to use the special tool to remove and instal the rotor
-
Sure.
This article will tell you all you need to know, including graphics!
http://www.airheads.org/content/view/194/98/
-
I talk with Rick again this morning and he suggest to buy a new multimeter.What a surprise :othe new one shows 3.7 ohms.I guess my multimeter and my vdo gauge get broken in the same time. :)
Thank you for your help guys
-
I had that problem, chasing a hard starting problem with my '81 R65, the meter I had, showed the proper resistance for the ignition coil, 1.5 ohms .
It was suggested that I get a known good meter to check out the coil .
I brought the coil to work, and checked it with a calibrated Fluke meter, and found the coil to have about a third of the resistance it should have .
Troubleshooting can get tough, when your test equipment isn't right !!!!!!