Question about 1983 BMW R 100 RT

1 Answer

I have a 1983 BMW R100RT. Potential charging problem

I have a 1983 BMW R100RT. Recently, the voltmeter started hovering just above 12 volts. Normally, it reads just shy of 13 volts. Five weeks ago, I replaced the turn signal solenoid. About two years ago, I replaced the diode board with an aftermarket one from Motorrad Elektrik. Questions: 1) Does a voltmeter reading just above 12 volts indicate a charging problem?
2) Is there anything specific to look for?
3) How should I go about trouble shooting the problem?
Thanks,
Tom

Posted by on

1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    MVP:

    An expert that got 5 achievements.

    Governor:

    An expert whose answer got voted for 20 times.

    Scholar:

    An expert who has written 20 answers of more than 400 characters.

  • Expert
  • 35 Answers

Hi Tom,

Typically, the charging voltage should be somewhere around 13.5VDC-14.5VDC, so you may be experiencing signs of a problem.

Before doing much else, I'd recommend you do two checks:
1) Assuming you are referring to a voltmeter mounted to the bike in your message, double check the voltage using a multimeter at the battery terminals to confirm there isn't a fault with your bike's voltmeter.

2) Because I'm unfamiliar with your particular model, I'd recommend checking the spec for your bike -- if you have a service manual, it should list the proper voltage range. Otherwise, you can probably contact a dealer or BMW tech to get the spec.

If you are below the recommended voltage range, there are a variety of possible faults.

The first that comes to mind is your regulator/rectifier circuit. The purpose of this circuit is to 1) rectify (turn the AC current generated by the engine into DC current) and 2) regulate (make the current stable at a given voltage, say 13.5 VDC, and dissipate the excess voltage as heat). Because this part turns excess electricity into heat, it's not uncommon for regulators to 'burn out."

I believe the diode board you replaced is the rectifier portion of the circuit, so it sounds like the regulator portion may need replacement. FYI, an aftermarket "reg/rec" that combines the regulator and rectifier is available for your bike (see: http://www.electrexworld.co.uk). The advantage to switching to such a unit is that it's probably better engineered than the OEM unit (more efficient/better heat dissipation), and might last longer.

If your battery is more than a few years old, you may want to take it to a dealer or auto parts store to have checked (many will do this for free), and consider replacing it. Often one bad component in the charging system will cause other good components to fail.


Finally, here is a generic fault finding diagram that is very well put together:
http://www.electrexworld.co.uk/pdfs/Troubleshooting-3P-PMG-&-RR.pdf

Good luck!

Posted on Sep 30, 2009

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Something's draining battery I go out to my car at lunch and only Bluetooth or radio is on and battery is dead in 5 mins.battery checked and it's good car has no battery issues except that


So you had the battery tested? Possibly the alternator or charging system is not up to par? Before you assume there is a drain, first make sure both battery and charging system are working good.

Best to buy a cheap voltmeter (or multifunction meter) to do any testing. Put a voltmeter on the battery, with key off, volt reading should be at least 12.4 volts-any less, like below 12 volts, then battery is not taking full charge OR the charging system is at fault. Now start the car and put voltmeter on the battery again: the reading should be at least 13.5 volts- somewhere between 13.5 and 14.5 volts. If it is, then charging system is good. If both battery and charging system check out, then you start looking for an unintended drain. YouTube has lots of videos on how to find an unintended drain.

Feb 25, 2017 | Cars & Trucks

1 Answer

Adjusting shocks


Hi, Anonymous I am sorry you can't find the first and best tool you ever bought for your BMW but despair not for a mere $0 you can download another one. For more information about your issue, please visit the websites below. Good luck and have a nice day.
Source for rear shocks for 1983 R100RT Vintage BMW Motorcycle Owners
R100 twinshock rear shock upgrade
Free BMW Motorcycle Service Manuals for download
BMW Motorcycle Parts Fiche OEM BMW Motorcycle Parts online 1970 present BMW
http://www.bmw-motorrad.com/us/en/index.html?content=http://www.bmw-motorrad.com/us/en/services/manuals/manuals_main.html¬rack=1

Apr 21, 2014 | 1983 BMW R 100 RT

1 Answer

Circuit diagram tom


Hi, Anonymous I am sorry you can't find the first and best tool you ever bought for your BMW but despair not for a mere $0 you can download another one. For more information about your issue, please visit the websites below. Good luck and have a nice day.
BMW Airhead Motorcycle Alternator Repair
http://forums.bmwmoa.org/showthread.php?30035-Testing-a-Voltage-Regulator
Free BMW Motorcycle Service Manuals for download
BMW Motorcycle Parts Fiche OEM BMW Motorcycle Parts online 1970 present BMW
http://www.bmw-motorrad.com/us/en/index.html?content=http://www.bmw-motorrad.com/us/en/services/manuals/manuals_main.html¬rack=1

Oct 08, 2013 | 1983 BMW R 100 RT

1 Answer

Starter switch


Batteries are checked with a load tester not a voltmeter as you will read 12 volts with a dead cell. Also a fully charged batter should read 13.2 volts and not 12 volts as each cell generates 1.2 volts not 1 volt.

Aug 18, 2013 | Honda CRF 230 F Motorcycles

1 Answer

My BMW R100RS charge light comes on dimly what could be the problem. thanks Danie


Hi, Danie_naude in order to check out any main system electrical circuit, you have to start with a fully charged battery 12.5 volts or better, and be able to pass a load test if necessary.
1. Check battery terminals for damage or corrosion, check battery cables at "BOTH" ends for loose, corroded, or broken connectors, "INSIDE" and outside the cable harness, perform connector wiggle test and check cables with an ohmmeter if necessary.
2. Check the voltage drop at the battery when you hit the starter button, anything below 9 volts you might have a faulty battery.
3. Check voltage at the battery with the bike running at 3,600 RPM should be 14.3 to 14.7 volts. If you are not getting these numbers, you might have a faulty voltage regulator.
4. Make sure voltage regulator is grounded and functioning properly, watch the video below on how to test a voltage regulator.
5. Unplug the connector to the alternator and hook your multimeter leads to the alternator (pin/socket selection does not matter) set the multimeter to AC volts, at an idle the meter should read 16 to 20 volts AC. at 2,000 RPM 32 to 40 AC volts, 3,000 RPM 48 to 60 AC volts. If you are not getting these numbers, you may have a faulty rotor, follow step 6
6. Set the multimeter to OHM'S, connect one lead to the alternator (any pin/socket) and the other to a ground, the meter should read infinity. Connect both leads to the alternator meter should read 0.1 to 0.2 OHM'S. If you are not getting these numbers, you have a bad stator.
7. Check all wiring in the charging circuit for worn or chaffed spots and all wiring connectors in the circuit for corroded, broken, or loose pins/sockets, which is the # 1 offender.
For more information about your issue please visit the websites below. Good luck and have a nice day.
BMW Airhead Motorcycle Alternator Repair
Dim Gen Light on 84 R100RT
1970 1993 Bmw 2 valve Twins R45 R50 R60 R65 R75 R80 R90 R100 Motorcycle...
BMW Motorcycle Parts Fiche OEM BMW Motorcycle Parts online 1970 present BMW
http://www.bmw-motorrad.com/us/en/index.html?content=http://www.bmw-motorrad.com/us/en/services/manuals/manuals_main.html¬rack=1

Jun 13, 2011 | 1986 BMW R 100 RS

1 Answer

Battery is charged but no lights showing, lights show and bike turns over very slowly on jump leads, have i overcharged the battery, bike not been started for twelve months and battery was new then, i have...


Your battery might be toaast. Need to check the battery with a load on it. An volt meter hooked to the battery (good battery-12'8V) will tell you how much voltage drops when you hit starter button. SHouldn't go below 12. If you have a bad cell, the voltmeter wil drop to less than 10 V. Battery's dead/new battery req'd Hope this helps

Sep 04, 2010 | 1983 Honda GL 1100 Gold Wing

1 Answer

My 2000 Yamaha golf cart has 6-4cell 8 volt batteries. I did not leave the cart plugged in during the winter months. When I attempted to charge yesterday, the charger lights sequenced but stayed on...


Yes to both questions. the charger must sense 41.5 volts to activate the relay inside the charger. Being a repair shop, I have a charger that is rigged to charge even DEAD batteries. I do not recommend this for the novice. A charger set on 12 volts will bring the batteries back up to 8.2-8.6 volts. A cheap trickle charger may not put out enough to charge a battery of this size. Remember that they are used to MAINTAIN a charge. Connect the Voltmeter and watch for voltage rise. If it rises to 8.1 or above, it is charging. Trojan battery company recommends charging at least once a month.

Apr 06, 2010 | 2000 Ford Focus

1 Answer

I need the torque values for the nuts securing the valve covers and for the center stud cap nut for a 1983 BMW R100RT.


Rocker cover cap nuts are torque to 22 / 26 Nn and the 6 mm threaded valve cover nuts should be 10 - 20 Nm
Ride Safe
Bike-Doc

Please mark this as useful (if it has been!!)

Aug 02, 2009 | 1983 BMW R 100 RT

2 Answers

2006 Chevy Silverado alternator intermittent charging


Perfectly normal.
Starting with the 2005 model year, light duty full size pickups and utilities are equipped with a new Regulated Voltage Control (RVC) system. This system reduces the targeted output of the generator to 12.6-13.1 volts when in "Fuel Economy Mode" to improve fuel economy. The generator may exit "Fuel Economy Mode" if additional voltage is required. This will cause the voltmeter to fluctuate between 12 and 14 volts as opposed to non-regulated systems that usually maintain a more consistent reading of 14 volts. This fluctuation with the RVC system is normal system operation and NO repairs should be attempted.

Jan 03, 2009 | 2006 Chevrolet Silverado

1 Answer

Check lights


It could be from a few issues. It definitely has to do with either the generator not working properly (recharging the battery, or a faulty battery not holding a charge. If you happen to have a voltmeter, you can test the battery voltage before you start the truck (should be about 12 volts), then test it while the truck is running (should be reading around 14 volts) this will mean the generator is charging the battery. Most batteries last about 3-5 years on average. If the voltage is not above 12 volts when the truck is running, the generator is bad, and you could get stuck with a dead battery.

Aug 09, 2008 | 1997 Dodge Ram 1500 Club Cab

Not finding what you are looking for?
1983 BMW R 100 RT Logo

996 people viewed this question

Ask a Question

Usually answered in minutes!

Top BMW Experts

Arnie Burke
Arnie Burke

Level 3 Expert

4514 Answers

yadayada
yadayada

Level 3 Expert

74896 Answers

phil cuzins
phil cuzins

Level 2 Expert

79 Answers

Are you a BMW Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...