charging

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Neal Cooper
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charging

Postby Neal Cooper » Thu Nov 08, 2018 12:43 am

Hi to all,
I have an R100RS 1978 with 54000 on clock.
The other day I got a high reading on my multimeter over 16 volts with engine running (R100 RS 1978), having had a couple of flat battery situations... so that would indicate that the voltage regulator is playing up, right? It appears to be irregular as on another occasion the voltage at the battery with the engine running appeared normal. Nevertheless the battery was flat again today. Voltmeter on dash sits at around 11 when riding with lights on and 12 with them off.
I checked out the regulator, took it off the bike and the contacts underneath were green. I opened it up and all looked ok. The points were in good shape and nothing seemed out of place.
I'm thinking of fitting a reg/rectifier upgrade. Anyone done this? If so how did you connect it up to the ignition switch?
I will start the bike with the mechanical regulator back in place and see what readings I get. Battery must be knackered too I guess though.
Any thoughts on this welcome.
Regards...
Neal

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SteveD
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Re: charging

Postby SteveD » Thu Nov 08, 2018 5:23 am

If the reg is kaput then it might've cooked the battery. The intermittency suggests a connection problem and the green stuff helps that thought.
In the past I had a problem like yours and it was just the earth connection not quite right. Fixing that connection sorted the issue. The battery survived for a couple of years too.
Cheers, Steve.
1982 R100RS, 2006 K1200R.
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Galactic Greyhound
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Re: charging

Postby Galactic Greyhound » Thu Nov 08, 2018 10:33 am

Hi Neal,

A high Alternator voltage (16v) at the Battery can also be indicative of corroded battery connections.
Corroded Battery connections can also appear to be a flat Battery as a high load e.g. Cranking or Headlights, will cause a large voltage drop across the corrosion.

Clean the Battery terminals AND the leads to bright metal.

The green corrosion on the Regulator is conductive and needs to be thoroughly cleaned off.

Also, as SteveD has posted, check and clean the main earth connection both at the Battery AND at the Gearbox earthing connection.
I think that this earth cable goes onto the speedo drive lug on the gearbox - if so, be very wary of stripping threads on the hollow vent bolt/lug!

Don't even think about upgrading the Rectifier/Regulator until you have found this problem as you may just be trying to mask a fault!
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: charging

Postby Mjolinor » Thu Nov 08, 2018 10:42 am

I have just been through this. Mine wasn't charging too well and had the mechanical regulator so I bought one of the red plastic ones off ebay and swapped it out. I suspect it didn't help but I am quite sure that connecting the previously disconnected earth lead from the alternator to the frame via the regulator mounting lug did help. D'oh

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Rob Frankhamr
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Re: charging

Postby Rob Frankhamr » Thu Nov 08, 2018 11:34 am

I would concur with the assesments above... Overcharging is caused by failure of the voltage regulator to... well... regulate the voltage but that isn't necessarily down to the regulator itself. One thing you can breathe easily about is that the overcharge means the alternator itself is probably fine.

Now I'm assuming that the charge circuit has been working OK up to now and that this is a new problem from which we can assume in turn that no one in the past has messed around with the wiring... otherwise all bets are off!

As I say, the regulator isn't regulating and the most likely reason is that the regulator ground is not connected. This could be due to a number of things.. dirty connections, broken wires or simply connectors that have come adrift.

The ground for the regulator goes from the regulator terminal block to the brush connectors at the top of the alternator under the front cover. The first thing you need to do, therefore, is to check the continuity of that wire. The best way to do it is to remove the front cover and check with a meter or test lamp for continuity between the two connectors, however, if you're in a hurry, a check between the regulator ground terminal and bare metal on the engine will give you a pretty good starter for ten. If the ground is OK, then you need to look for other reasons.

As said above, the engine and battery grounds need to be clean and properly attached.

A seriously flat battery will cause overvoltage but, if the battery is starting the bike when fully charged, that almost certainly isn't the problem.

That brings us, finally, to the regulator itself. If you've done the tests above, it's reasonable to suspect that the regulator itself is defective. It is quite difficult to test a voltage regulator off the machine unless you have test equipment and electrical knowledge, the easiest way to prove the fault is to substitute a known good unit on the bike. If you can get access to a spare, then well and good but if not, you'll have to buy one.

It's not the end of the world. (I'd recommend you replace it anyway with an electronic replacement... they have a better performance). If you go to one of the usual three suppliers, a new electronic regulator will set you back about fifty squids but... these are generic parts. You can get essentially the same part from an online auto electronic supplier for a quarter of that. It won't have BMW or Bosch written on it but it will work just as well. One source is Vehicle Wiring Parts (VWP) http://www.vehicle-wiring-products.eu/s ... /electrics

I would suggest, given the state of the terminals on the regulator block, that you need to carry out a campaign, cleaning up all of the connections on the bike but I can't think of anything else specific to this fault. Don't bother with an aftermarket Regulator/Rectifier. No matter what is claimed, it won't give any advantage over a properly functioning stock system...

Rob
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Mjolinor
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Re: charging

Postby Mjolinor » Thu Nov 08, 2018 12:09 pm

I would add that given the age of these bikes testing for good connections is much better done with a bulb. A meter can read but as soon as you draw a significant current old connections and wires can fail and then go OK again once you remove the load, there is no significant load if you just use a meter to test.

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Galactic Greyhound
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Re: charging

Postby Galactic Greyhound » Thu Nov 08, 2018 1:59 pm

+1 :grin:
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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windmill john
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Re: charging

Postby windmill john » Thu Nov 08, 2018 3:00 pm

Cor blimey, mjolinor's turned into Ced!

They must have shares in 12V bulbs :grin:
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Best roads: 623 Burgos to Santander. A back road to Metz; can't remember which!
Schorsch - 1978-80 R65 - bit of a Shetland pony; frisky and naughty.
Max - 2009 F800GS- where’s the desert at!?
Too many bikes have come and gone, trying to be sensible now!

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Galactic Greyhound
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Re: charging

Postby Galactic Greyhound » Thu Nov 08, 2018 3:04 pm

Very illuminating John! :lol:
Ced.

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

Roy Gavin
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Re: charging

Postby Roy Gavin » Fri Nov 09, 2018 6:30 am

Blame Boyer, it started on their site.
I must have been lucky, but the only wire I have ever found that had continuity but wouldn't pass sufficient current was a internally corroded battery lead , a long time ago when we had to use wet acid batteries which corroded everything.
If you switch the multitester to volts voltage drop can be a sign that you have a problem too.

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Re: charging

Postby Mjolinor » Fri Nov 09, 2018 10:09 am

It isn't just corrosion that leads to the problem. Modern wires that are used in cars and bikes are not very flexible, they don't handle vibration well. I suppose if you live in a desert :) then perhaps you would only meet one every lifetime but I have seen hundreds and they can be diabolical to find.

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Rob Frankhamr
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Re: charging

Postby Rob Frankhamr » Fri Nov 09, 2018 11:15 am

The 'best' one is when the conductor fractures but makes good, but intermittent, contact.

I had this once on an R45. The bike would run perfectly then for no apparent reason die completely then restart a short time later (sometimes before the bike even came to a halt) to run perfectly again till next time. Every test I tried showed no untoward results. Eventually, I tracked it down to the main power lead to the ignition switch which had broken in the vicinity of the steering head. The eventual diagnosis was down to pure luck really... I was on the bike stationary with the engine running. I just happened to move the bars slightly and everything went dead. Another slight bar movement and it all came back again. From that, I was able to find that if I pulled the loom in a certain way, I could reproduce the symptoms and after that it was, as they say, plain sailing.

Rob
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IanG
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Re: charging

Postby IanG » Fri Nov 09, 2018 3:51 pm

Just to throw a curve ball. Some digital meters do not like all the "noise" going on in vehicle electrical systems, particularly cheaper ones. I have a cheap one that reads over 16 volts with engine running but with a decent meter the voltage is a more sensible 14 ish. I'd try and borrow another meter before you start spending.

Ian
1983 R100
1955 Norton ES2
1972 Norton Commando
2001 Honda VFR800
19** Understanding wife

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Re: charging

Postby Mjolinor » Fri Nov 09, 2018 4:51 pm

I think my Fluke is thirty years old this year, it has never missed a beat, never does anything wrong, that s a model 75,. A few years ago the military disposed of some model 25 flukes and they were about £2 per truck load at every flea market. I bought a few and actually wanted another a few months ago, they are now very hard to find but without doubt if you can find one those Fluke 25s are excellent basic metres.

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windmill john
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Re: charging

Postby windmill john » Fri Nov 09, 2018 5:24 pm

And the test leads...

If you get a crappy pair, it quite amazing the difference in readings on the resistance scale for example.
http://www.kittos.co.uk
Best roads: 623 Burgos to Santander. A back road to Metz; can't remember which!
Schorsch - 1978-80 R65 - bit of a Shetland pony; frisky and naughty.
Max - 2009 F800GS- where’s the desert at!?
Too many bikes have come and gone, trying to be sensible now!

Roy Gavin
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Re: charging

Postby Roy Gavin » Fri Nov 09, 2018 10:42 pm

Just done Robs intermittent fracture routine on the starter button of my R75/7.
Ended up bypassing the rats nest in the headlamp shell and the harness and and wiring it direct.
On my well worn G/S I recently grasped the nettle and replaced the lot, wiring, switches, PCB, relays, etc, should have done it as soon as I bought the bike!


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