1982 R65LS mystery battery/charging problem

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1982 R65LS mystery battery/charging problem

Postby Goldbug101 » Thu Jun 11, 2015 6:31 pm

Hi all.

Much as I'd love to own a beemer I don't, but a friend of mine does and he's not very techie and has never used a forum before, so I said I would help him.

This old bike is still going strong after 33 years and had a new BMW Exide battery fitted last year.

We went for a rideout recently and after one stop the engine would barely turn over, but did fire and start. After the next stop it wouldn't start at all and it had to be bump started, which worked.

So my chum took the bike to some good old boys who run a local motorcycle museum and also service and repair bikes. He's used them for a while and seems happy with them.

They can't find anything definitive wrong, but suspect the charging system. Mind you, the guy who was working on it swore blind that "these old beemers don't have alternators, they have dynamos", which worried me somewhat, especially as he then gestured to where the diodes are located! Why a bike with a dynamo would need diodes is beyond me.

So, we got the bike home and I went round with my digital battery analyser and took the battery out. That tested fine, so I put it back in and tested the starting circuit. A-OK. Next the charging circuit. With the engine started, the battery voltage quickly dropped from a healthy 12.75v to 9.66v. At no time did the charging voltage rise above 12.75v, even revving the engine.

I should add that at no time does the battery warning light come on on the dash. Mind you, I didn’t check to see if the bulb's gone. Should it light up when the ignition is turned on and go out when the engine is started, all being well?

If charging light is okay then, according to the Book of Hayne, the regulator/rectifier is probably ok, but the alternator or its diode pack may be faulty.

That's where we are at the moment.

It's a nice simple bike with reasonably accessible guts, so hopefully this is something we can sort out easily, especially with your inestimable assistance.

I look forward to reading your thoughts and suggestions shortly.

Thanks guys.
2015 F800GT - Oct 2018
2015 R1200RT LE LC - Oct 2015 & G310R - 2018
2003 R1150RT - Sept 2015
Honda NT700VA-8 Deauville - Feb 2015
Honda ST1100 Pan European - 2003
Honda CX500 - 1981
Honda CB250N Superdream - 1979
Honda CB200 - 1978

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Re: 1982 R65LS mystery battery/charging problem

Postby Galactic Greyhound » Thu Jun 11, 2015 7:06 pm

Hi nicksoldbeemer,

The 1982 R65LS has a 3-phase alternator running off the end of the crankshaft at the front of the engine and an electronic ignition system.

The output of the alternator is rectified by the Diode Board at the top front of the engine under the front cover - ALWAYS disconnect the battery earth before removing/refitting this cover as it is easy to short out the battery otherwise.

The alternator rotor current is controlled by a Regulator unit and so controls the alternator output. You can disconnect and short the Regulator DF and D+ wires together to bypass the Regulator and check if the system charges without it so proving if the Regulator is faulty or not.

With the engine running at around 2000 rpm you should see 14 - 14.5v across the battery terminals if the alternator is charging.

When the ignition is switched on, the Charge Light should illuminate. If it does not, then there is a fault in the alternator rotor circuit, the Regulator or the Charge Light bulb has failed (not a common fault).

The most likely cause of not charging is rotor brushes failing to make contact with the rotor slip rings or the rotor winding has failed. Both of these faults are quite common. The rotor should have a resistance of around 3 ohms measured across the slip rings.

Here is a diagram of a typical Airhead Charging Circuit which should allow you to test the circuit:

Click to Enlarge/Save As
Airhead Charging Circuit.jpg
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R1100RT 1996.
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Re: 1982 R65LS mystery battery/charging problem

Postby Goldbug101 » Thu Jun 11, 2015 7:14 pm

Thanks for speedy reply, GG.

Definitely not getting >12.75 at battery when revs up at 2k.

Given the age of the bike (not sure of mileage), would you tend to favour worn brushes? Are they easily replaceable?

Otherwise I guess faulty regulator could be holding output voltage down?

Thanks
2015 F800GT - Oct 2018
2015 R1200RT LE LC - Oct 2015 & G310R - 2018
2003 R1150RT - Sept 2015
Honda NT700VA-8 Deauville - Feb 2015
Honda ST1100 Pan European - 2003
Honda CX500 - 1981
Honda CB250N Superdream - 1979
Honda CB200 - 1978

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Re: 1982 R65LS mystery battery/charging problem

Postby Galactic Greyhound » Thu Jun 11, 2015 7:31 pm

Thanks for speedy reply, GG.

Definitely not getting >12.75 at battery when revs up at 2k.

OK - the alternator circuit is not charging.

Given the age of the bike (not sure of mileage), would you tend to favour worn brushes? Are they easily replaceable?

The most likely cause is worn/sticking brushes or an open-circuit rotor.

Otherwise I guess faulty regulator could be holding output voltage down?

Regulator problems are not common however the Regulator can be by-passed as described previously to eliminate it.

Thanks
Here is a link to Snowbum's Alternator troubleshooting article:
http://bmwmotorcycletech.info/trbleshootALT.htm


Here is an article I wrote on faulting charging problems - look down the article for the section '2. CHARGE LIGHT DOES NOT ILLUMINATE':

Airhead Charging Circuit - Faulting.txt Issue: 26/01/2015

Author: Galactic Greyhound
Date: 29/05/2014


See the attached diagram; 'Typical Alternator Charging Circuit' below.

1. CHARGE LIGHT ON CONTINUALLY:

The charging circuit components which may be causing the non-charging problem are:
1. The Alternator Rotor.
2. The Regulator.
3. The Alternator Stator.
4. The Diode Board.

ROTOR CIRCUIT TESTS:
The Charge light is illuminated from the Battery 12v+, through the Ignition Switch, Charge light, Regulator (D+ & DF) and the Alternator Rotor to earth. However, any short to earth on the Rotor
side of the Charge light will cause the light to remain lit continually and prevent the Alternator from charging the Battery.

WARNING: Do NOT remove the front engine cover without first disconnecting a battery terminal. This is because the Diode Board has a metal heatsink connected to the +12v which can be
shorted to earth by removal of the front cover.

TEST A:
To determine if there is an earth short on the Rotor side of the Charge light which is causing the problem, remove the front engine cover to access the Alternator and perform the following test:
1. Switch On the Ignition (engine not running) and observe that the Charge light is lit.
2. Disconnect the D- earth wire (Brown wire) from the Rotor brush connection.
3. The Charge light should go out - if it does so, then there is NO earth fault on the Rotor side of the Charge light.
4. However, the other thing to consider in the Rotor circuit is that the Rotor has gone short-circuit. This will prevent the Alternator from charging. Lift one brush clear of the Rotor sliprings and then
measure the resistance across the sliprings - the Rotor resistance should be around 3 ohms.


TEST B:
If the Charge light does NOT go out when the D- earth wire (Brown wire) from the Rotor brush connection is disconnected, perform the following test:
1. Switch On the Ignition (engine not running) and observe that the Charge light is lit.
2. Disconnect the DF wire (Blue/Black wire) from the insulated Rotor brush connection.
3. The Charge light should go out - if it does, there is an earthing fault in the DF insulated connection or in the Rotor.

TEST C:
If the Charge light does NOT go out when the DF wire (Blue/Black wire) is disconnected from the insulated Rotor brush connection, perform the following test:
1. Switch On the Ignition (engine not running) and observe that the Charge light is lit.
2. Disconnect the DF wire (Blue/Black wire) from the Regulator DF terminal.
3. The Charge light should go out - if it does, there is an earthing fault in the DF Blue/Black wire to the Rotor.

TEST D:
If the Charge light does NOT go out when the DF wire (Blue/Black wire) is disconnected from the from the Regulator DF terminal, perform the following test:
1. Switch On the Ignition (engine not running) and observe that the Charge light is lit.
2. Disconnect the D+ wire (Blue wire) from the Regulator D+ terminal.
3. The Charge light should go out - if it does, there is an earthing fault in the Regulator.

TEST E:
If the Charge light does NOT go out when the D+ wire (Blue wire) is disconnected from the Regulator D+ terminal, perform the following test:
1. Switch On the Ignition (engine not running) and observe that the Charge light is lit.
2. Disconnect the D+ wire (Blue wire) from the Regulator D+ terminal AND disconnect the D+ wire (Blue wire) from the Diode Board.
3. The Charge light should go out - if it does, there is an earthing fault in the Diode Board.

TEST F:
If the Charge light does NOT go out when the D+ wire (Blue wire) is disconnected from the Regulator D+ terminal AND the Diode Board D+ terminal, perform the following test:
1. Switch On the Ignition (engine not running) and observe that the Charge light is lit.
2. Disconnect the D+ wire (Blue wire) from the Rotor side of the Charge light holder.
3. The Charge light should go out - if it does, there is an earthing fault in the D+ wire itself from the Regulator or the Diode Board.

TEST G:
If the Charge light does NOT go out when the D+ wire (Blue wire) is disconnected from the Rotor side of the Charge light holder, then the holder is earthed on the Rotor side.



REGULATOR TESTS:
In case the Regulator is faulty and preventing the Alternator from charging, perform the following tests:

TEST A:
1. Disconnect the D+ and DF wires from the Regulator and join these wires temporarily together so as to bypass the Regulator completely.
2. Start the engine and see if the Charge light goes out - if so, the Regulator is likely faulty.



STATOR TESTS:
In case the Stator is faulty and preventing the Alternator from charging, perform the following tests:

WARNING: Do NOT remove the front engine cover without first disconnecting a battery terminal. This is because the Diode Board has a metal heatsink connected to the +12v which can be
shorted to earth by removal of the front cover.

TEST A:
1. Disconnect the Stator U, V, W and Y leads after noting down where they are connected to the Diode Board.
2. Measure the resistance between each stator winding (U, V & W) and the Y connection. The Stator windings U, V and W should have a resistance of around 0.65 ohms each.
All windings should show the same reading.


TEST B:
1. Disconnect the Stator U, V, W and Y leads after noting down where they are connected to the Diode Board.
2. Switch On the Ignition (engine not running).
3. With the engine running at about 2000 rpm and your voltmeter set to read around 30v AC [Note AC not DC], measure the voltage across each Stator winding (U, V and W) to earth - you
should see over 12v on each winding and the voltage should be the same for each winding.



DIODE BOARD TESTS:
See the link below for an article by Rob Frankham on how to test this component. First check that all the wires have been correctly connected before you start removal and testing particularly
the 'Y' earth connection. Keep a note of what wire is connected where:

http://www.frankhams.freeserve.co.uk/te ... _board.htm



2. CHARGE LIGHT DOES NOT ILLUMINATE:

The Charge light is illuminated from the Battery 12v+, through the Ignition Switch, Charge light, Regulator (D+ & DF) and the Alternator Rotor to earth.

TEST A:
To determine if there is an open circuit on the Rotor side of the Charge light which is causing the problem, remove the petrol tank to access the Regulator and perform the following test:
1. Switch On the Ignition (engine not running) and observe that the Charge light is not lit.
2. Disconnect the D+ wire (Blue wire) from the Regulator D+ terminal and connect the wire to earth.
3. The Charge light should illuminate - if it does, the break is further on towards the Rotor.
4. The Charge light should illuminate - if it does NOT, the break is back towards the Charge light. Check the Charge light bulb is not blown or the bulb holder connections.

TEST B:
If the Charge light illuminates when the D+ wire (Blue wire) is disconnected from the Regulator D+ terminal and earthed, perform the following test:
1. Switch On the Ignition (engine not running) and observe that the Charge light is not lit.
2. Disconnect the DF wire (Blue/Black wire) from the Regulator DF terminal and connect an earth to the Regulator DF terminal.
3. The Charge light should illuminate - if it does, the break is further on towards the Rotor.

TEST C:
If the Charge light illuminates when an earth is connected to the Regulator DF terminal, remove the front engine cover to access the Alternator and perform the following test:

WARNING: Do NOT remove the front engine cover without first disconnecting a battery terminal. This is because the Diode Board has a metal heatsink connected to the +12v which can be
shorted to earth by removal of the front cover.

1. Switch On the Ignition (engine not running) and observe that the Charge light is not lit.
2. Disconnect the DF wire (Blue/Black wire) from the insulated Rotor DF brush connection and connect this wire to earth.
3. The Charge light should illuminate - if it does, the break is further on into the Rotor.

TEST D:
If the Charge light illuminates when an earth is connected to the Rotor DF wire, perform the following test:
1. Switch On the Ignition (engine not running) and observe that the Charge light is not lit.
2. Disconnect the D- wire (Brown wire) from the earthed Rotor brush connection and connect an earth to this brush connection.
3. The Charge light should illuminate - if it does then the earth connection to the brush is faulty.
4. The Charge light should illuminate - if it does NOT then the path through the Rotor is faulty - check that the brushes are making contact with the slip ring, the slip rings are clean and the Rotor
resistance is approximately 3 ohms.

[attachment=0]Airhead Charging Circuit.jpg[/attachment]

REFERENCES:
A. Airhead Charging Circuit - http://bmwmotorcycletech.info/trbleshootALT.htm
B. Testing the Diode Board - http://www.frankhams.freeserve.co.uk/te ... _board.htm
C. Bosch Charging Systems - http://www.buchanan1.net/charge.shtml
D. Testing Voltage Regulators - http://bmwmotorcycletech.info/testingvo ... lators.htm
E: Rotor, Stator & Brushes - http://bmwmotorcycletech.info/altbrushrotor.htm
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R1100RT 1996.
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Re: 1982 R65LS mystery battery/charging problem

Postby Goldbug101 » Thu Jun 11, 2015 7:33 pm

Pan-galactic gargle-blasting stuff, GG, will work my way through it.

Thanks a lot.
2015 F800GT - Oct 2018
2015 R1200RT LE LC - Oct 2015 & G310R - 2018
2003 R1150RT - Sept 2015
Honda NT700VA-8 Deauville - Feb 2015
Honda ST1100 Pan European - 2003
Honda CX500 - 1981
Honda CB250N Superdream - 1979
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Re: 1982 R65LS mystery battery/charging problem

Postby Galactic Greyhound » Thu Jun 11, 2015 7:38 pm

Pan-galactic gargle-blasting stuff, GG, will work my way through it.

Thanks a lot.
With the Charge Light not illuminating at Ignition On, this is the easiest fault to find - all you need to do is apply an earth at various points as per my article, watch the Charge Light, and you will isolate the problem area quite easily - no skill required! :grin:

Look at the diagram as you work through it and you will see what is happening.

Let us know how you get on.
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" - It works!

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Re: 1982 R65LS mystery battery/charging problem

Postby Goldbug101 » Thu Jun 11, 2015 7:39 pm

Ok, will do.

You da man
2015 F800GT - Oct 2018
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2003 R1150RT - Sept 2015
Honda NT700VA-8 Deauville - Feb 2015
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Re: 1982 R65LS mystery battery/charging problem

Postby Goldbug101 » Thu Jun 11, 2015 7:44 pm

Quickie: what is meant by /5 when referring to a bike? Not year, I presume? Is it model variant and if so how does that work?
2015 F800GT - Oct 2018
2015 R1200RT LE LC - Oct 2015 & G310R - 2018
2003 R1150RT - Sept 2015
Honda NT700VA-8 Deauville - Feb 2015
Honda ST1100 Pan European - 2003
Honda CX500 - 1981
Honda CB250N Superdream - 1979
Honda CB200 - 1978

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Re: 1982 R65LS mystery battery/charging problem

Postby Galactic Greyhound » Thu Jun 11, 2015 7:57 pm

Quickie: what is meant by /5 when referring to a bike? Not year, I presume? Is it model variant and if so how does that work?
The /5 is an Airhead model series e.g. R50/5, R60/5 and R75/5
Link: http://en.wikipedia.org/wiki/BMW_/5_motorcycles

There were other '/-Series' bikes produced as well such as the /6 and the /7.

http://en.wikipedia.org/wiki/BMW_/6_motorcycles

Phil's (Boxerman) BM Bikes info:
http://www.bmbikes.co.uk/bmwmodels.htm

Snowbum's take on it:
http://bmwmotorcycletech.info/models.htm
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" - It works!

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Re: 1982 R65LS mystery battery/charging problem

Postby Goldbug101 » Thu Jun 11, 2015 8:04 pm

Ok, got it, I think, but how does R65 fit into that schema? Would/could it in fact be an R65/5?

Sorry to seem dim, but these questions rarely arise in the world of japcrap!
2015 F800GT - Oct 2018
2015 R1200RT LE LC - Oct 2015 & G310R - 2018
2003 R1150RT - Sept 2015
Honda NT700VA-8 Deauville - Feb 2015
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Honda CX500 - 1981
Honda CB250N Superdream - 1979
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Re: 1982 R65LS mystery battery/charging problem

Postby Galactic Greyhound » Thu Jun 11, 2015 8:23 pm

Ok, got it, I think, but how does R65 fit into that schema? Would/could it in fact be an R65/5?

Sorry to seem dim, but these questions rarely arise in the world of japcrap!
Hi,

Well you have a bit more history to deal with in BMW! :lol:

There was an R60/5 but there was never an R65/5, just the R65 Series.

The R65 is another BMW bike series, I think after the slash (/) series bikes were phased out:
http://en.wikipedia.org/wiki/BMW_R65

The Airhead guys will hopefully be able to explain things to you a bit better than I can! :grin:
Last edited by Galactic Greyhound on Thu Jun 11, 2015 8:27 pm, edited 1 time in total.
Ced.

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Re: 1982 R65LS mystery battery/charging problem

Postby Goldbug101 » Thu Jun 11, 2015 8:27 pm

Achtung - Panzer!
2015 F800GT - Oct 2018
2015 R1200RT LE LC - Oct 2015 & G310R - 2018
2003 R1150RT - Sept 2015
Honda NT700VA-8 Deauville - Feb 2015
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Honda CX500 - 1981
Honda CB250N Superdream - 1979
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Re: 1982 R65LS mystery battery/charging problem

Postby Galactic Greyhound » Thu Jun 11, 2015 8:28 pm

Achtung - Panzer!
That's why they are such good bikes - they got a proper work out!
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" - It works!

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Re: 1982 R65LS mystery battery/charging problem

Postby Goldbug101 » Thu Jun 11, 2015 8:30 pm

Achtung - Panzer!
That's why they are such good bikes - they got a proper work out!
Like VW Beetles! =D>
2015 F800GT - Oct 2018
2015 R1200RT LE LC - Oct 2015 & G310R - 2018
2003 R1150RT - Sept 2015
Honda NT700VA-8 Deauville - Feb 2015
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Honda CB250N Superdream - 1979
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Re: 1982 R65LS mystery battery/charging problem

Postby Galactic Greyhound » Thu Jun 11, 2015 8:47 pm

Indeed!

If you are interested in the history of BMW motorcycles then see this Wikipedia link:
http://en.wikipedia.org/wiki/History_of_BMW_motorcycles

It is interesting to note that between 1948 and 1952 there were TWO different BMW companies producing motorcycles under the SAME BMW name! (It would never happen in Japan!)
One company was in the Soviet Union (East Germany) and the other in West Germany producing virtually the same bike!
"No motorcycles made in East Germany after World War II were manufactured under the authority of BMW in Munich as there was no need for an occupying power to gain such authority (Wikipedia)".
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" - It works!

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Re: 1982 R65LS mystery battery/charging problem

Postby Goldbug101 » Thu Jun 11, 2015 8:49 pm

She-it! :shock:
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2015 R1200RT LE LC - Oct 2015 & G310R - 2018
2003 R1150RT - Sept 2015
Honda NT700VA-8 Deauville - Feb 2015
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Re: 1982 R65LS mystery battery/charging problem

Postby Goldbug101 » Fri Jun 12, 2015 6:30 pm

Lots of info downloaded and printed out, so we're going in to investigate Sat pm.

Spanners and multimeter at the ready.

Will report back in due course.

Wish us luck!
2015 F800GT - Oct 2018
2015 R1200RT LE LC - Oct 2015 & G310R - 2018
2003 R1150RT - Sept 2015
Honda NT700VA-8 Deauville - Feb 2015
Honda ST1100 Pan European - 2003
Honda CX500 - 1981
Honda CB250N Superdream - 1979
Honda CB200 - 1978

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Re: 1982 R65LS mystery battery/charging problem

Postby Goldbug101 » Sat Jun 13, 2015 4:58 pm

Well, mixed results after a couple of hours of tinkering and investigation:

1. Alternator brushes - are in good shape, plenty of travel left, springs sound, move freely, engage well on slip rings. Stator out and inspected, all well, if dirty.

2. Slip ring to ring resistance - quoted as around 3ohms. I was getting 6-7ohms, consistently.

3. Rotor circuit tests -

A. charge light goes out when D- removed from rotor connection.

B. charge light does go out when DF wire disconnected from rotor terminal, indicating earthing fault in DF connection or in rotor. Traced DF wire from rotor to regulator and did continuity test - checked out fine.

D. Charge light did not go out, which rather undermined result of test B.

Found a frayed wire under top tube near a connector as referenced elsewhere. Not broken, but rubbing on frame. Cut it out and replaced with a connector. Didn't solve anything, sadly.

Didn't bypass the regulator on this occasion as out of time. Reassembled and restarted, hoping that disconnecting and reconnecting various things might have fixed the problem. Voltage at battery with engine at 2k RPM still 12.75v, however.

So, rather inconclusive results, with only rotor resistance and DF wire in test B suggesting that all not well.

Scratching head now - any ideas?

NOB
2015 F800GT - Oct 2018
2015 R1200RT LE LC - Oct 2015 & G310R - 2018
2003 R1150RT - Sept 2015
Honda NT700VA-8 Deauville - Feb 2015
Honda ST1100 Pan European - 2003
Honda CX500 - 1981
Honda CB250N Superdream - 1979
Honda CB200 - 1978

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1982 R65LS mystery battery/charging problem

Postby Galactic Greyhound » Sat Jun 13, 2015 7:20 pm

If the Charge Light is On CONTINUALLY at Ignition On and never goes Off but goes Off when the DF terminal is disconnected at the Rotor, then it is possible that the Rotor winding is earthing.
Disconnect the DF and D- (Earth) terminals at the Rotor. The Rotor winding should now be isolated from everything else. Measure the resistance from one slip ring to the Rotor shaft - if you can measure resistance to the Rotor shaft then the Rotor winding is earthing.

Alternatively, disconnect the D- (earth) connection to the Rotor with the Ignition On. If the Charge Light remains lit the Rotor may be earthing. Disconnect the Rotor DF connection, if the Charge Light goes Off then the Rotor is earthing.

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Re: 1982 R65LS mystery battery/charging problem

Postby Goldbug101 » Sat Jun 13, 2015 10:30 pm

Hi GG. Glad you're around today.

Ummmm. Let's see...

The charge light *does* go off once the engine is running, suggesting that the charging circuit is producing at least enough current to turn the lamp off.

I haven't tried testing between a slip ring and earth, only the impedance between the slip rings, which was 6-7ohms, rather than the nominal 3.

I suspect rotor earthing from the tests I did earlier and what you say, plus the out-of-spec impedance reading.

Can you buy a new rotor or have the existing one rebuilt/rewound? These things are pretty solid, how can they develop a leak to earth?
2015 F800GT - Oct 2018
2015 R1200RT LE LC - Oct 2015 & G310R - 2018
2003 R1150RT - Sept 2015
Honda NT700VA-8 Deauville - Feb 2015
Honda ST1100 Pan European - 2003
Honda CX500 - 1981
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Galactic Greyhound
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1982 R65LS mystery battery/charging problem

Postby Galactic Greyhound » Sat Jun 13, 2015 10:59 pm

If the Charge Light goes Off when running, then there must be some charging voltage being developed which you should be able to measure across the battery terminals.
Measure the voltage at Ignition Off, Engine at idle and Engine at 2000 rpm.

You can also measure the current through the Rotor at Ignition On (engine not running) which should be around 200 m/A.

If the Charge Light goes out then I do not think that the Rotor is earthing.

Bypass the Regulator and see if you can get the charging voltage into the 14 - 14.5 v range.

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Goldbug101
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Re: 1982 R65LS mystery battery/charging problem

Postby Goldbug101 » Sat Jun 13, 2015 11:01 pm

OK, GG, I will give that a try.

Bear in mind that voltage across battery terminals does not exceed 12.75v at 2kRPM.

Thx.
2015 F800GT - Oct 2018
2015 R1200RT LE LC - Oct 2015 & G310R - 2018
2003 R1150RT - Sept 2015
Honda NT700VA-8 Deauville - Feb 2015
Honda ST1100 Pan European - 2003
Honda CX500 - 1981
Honda CB250N Superdream - 1979
Honda CB200 - 1978

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Galactic Greyhound
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1982 R65LS mystery battery/charging problem

Postby Galactic Greyhound » Sat Jun 13, 2015 11:33 pm

OK - I am away for the weekend but back tomorrow and am on my iPhone which is not as good as my laptop with all the Wiring Diagram data.

If you cannot see the 14.5v charging voltage across the battery but the charge light is going out, I would suspect that the Diode Board B+ terminal might not be connected to your battery 12v+ terminal.
I'm going by memory on this and will check it out when I get home tomorrow.
The Diode Board has 2 outputs, a D+ output via the small diodes to the Regulator and the Charge Light, and a Higher current output B+ via the large diodes which does the actual battery charging.
If the D+ output is OK the Charge Light will go out but if there is a fault in the B+ circuit the battery will not charge and you will not see 14.5v across the terminals when charging.

You might measure the D+ voltage when charging to see if it gets to the 14.5v. If it does and the B+ voltage does not then the B+ wiring or Diode Board B+ diodes are suspect.

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Goldbug101
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Re: 1982 R65LS mystery battery/charging problem

Postby Goldbug101 » Sun Jun 14, 2015 8:55 am

You're a star. Thanks.

Will investigate and advise.
2015 F800GT - Oct 2018
2015 R1200RT LE LC - Oct 2015 & G310R - 2018
2003 R1150RT - Sept 2015
Honda NT700VA-8 Deauville - Feb 2015
Honda ST1100 Pan European - 2003
Honda CX500 - 1981
Honda CB250N Superdream - 1979
Honda CB200 - 1978

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DEEP DIVER
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Re: 1982 R65LS mystery battery/charging problem

Postby DEEP DIVER » Sun Jun 14, 2015 9:22 am

If you require rotors check out motorworks https://www.motorworks.co.uk/vlive/Shop ... Q=ELR44642
New and s/hand parts for bmw bikes.
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