The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Lucas, Ignition, Charging, Electrical => Topic started by: Worty on 20.05. 2018 19:24
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I know there's tons out there on this, and I've had a look for an answer but can't find much for this specific problem.
Battery is good and all electrics work ok. Bike was charging fine then stopped showing a charge (ammeter is new). Tried it again today and it worked normally, for a while, then stopped showing a charge again. Ammeter shows discharge with lights on. So, dynamo is functioning, ammeter is functioning, could it be the regulator. I have a DVR2 and all wires seem to be good as are earths. Have cleaned the commutator and brushes thoroughly. At a bit of a loss.
One other thing, is it fairly straightforward to replace a side trip meter shaft - mine broke!!
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May be a silly question, but what makes you think that the charging system isn't working as it should be?
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to Clarify what REX said
If working properly the regulator will show a discharge (On the Ammeter) when power is drawn from the battery then when the battery is charged sufficiently the regulator will cut out (showing no charge on the ammeter)
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Have you cleaned and checked the F and D connections on the dynamo (see photo). The F (field) and D (dynamo) wires go to F and D on your DVR2.
Edit: You may need a good handful of revs before the DVR2 cuts in and shows a charge on the ammeter.
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How’s the battery voltage behaving? Is it going down rapidly?
In the end that’ll tell you more about the charge it’s getting.
One other thing, is it fairly straightforward to replace a side trip meter shaft - mine broke!!
The trip meter shaft is a short piece of shaft poking out of the speedometer housing. The long shaft which you pull and turn slides over it and there’s a small spring pin holding both together. Big chance it’s just the pin that broke.
The short shaft has some kind of little gear inside the speedometer which, when pulled, connects to another gear to turn the trip meter to zero. Could be that the little gear came loose. If that’s the case, the speedometer has to be opened.
Both cases are not that complicated to repair.
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Thanks fellas - here's what I know.
When the lights are off, the ammeter will normally show a small charge then settle in the central position fairly quickly. When the lights are on, the ammeter will (normally) show a discharge at tickover then rise above the central position when revved (charging I guess). At present, the ammeter continues to show a discharge even when revved. I guess what you're all saying is that if the battery is fully charged, the ammeter will show a discharge as the regulator is detecting a fully charged battery and won't put charge into it. Only when the battery becomes sufficiently low will the regulator kick in and show a charge.
This does make complete sense, but is different to what's been happening up until now. Even on a long run, when I've turned the lights on, the ammeter shows a discharge at tickover and a charge when revved (lights brightening on revving). Perhaps the Westco battery is pants (I've had intermittent problems with Wescos before). By the way, I did do a 190m run on it yesterday so perhaps the battery has decided to become fully charged for a while??
Cheers for the reset shaft info. Mine was corroded badly around where the hole is for the extension. When I got back yesterday and tried to reset it, the end basically crumbled. Have spotted a stainless shaft on Ebay for a tenner which looks right.
Let me know if I've got this right. Lights are bright, by the way, which supports your comments.
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I know there's tons out there on this, and I've had a look for an answer but can't find much for this specific problem.
Battery is good and all electrics work ok. Bike was charging fine then stopped showing a charge (ammeter is new). Tried it again today and it worked normally, for a while, then stopped showing a charge again. Ammeter shows discharge with lights on. So, dynamo is functioning, ammeter is functioning, could it be the regulator. I have a DVR2 and all wires seem to be good as are earths. Have cleaned the commutator and brushes thoroughly. At a bit of a loss.
One other thing, is it fairly straightforward to replace a side trip meter shaft - mine broke!!
How old is your DVR2? I’ve got a suspect one which barely lasted through the engine running in....in your case though it sounds more like the dynamo or wiring is at fault.
Edit: as posts crossed over.......is your dynamo not able to keep up with the lights eg it’s showing a discharge when the lights are on and engine is (say) over 2000 rpm?
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Thanks kiwgf. DVR2 is 3.5 years old, but the dynamo did show a charge briefly today. Re your comment about the lights on, yes, it normally does show an immediate discharge followed by an immediate charge when revved. However, I get the point that if the battery is fully charged, the ammeter would show a discharge until the rego decides it's time to pump in more power. With the lights off, by the way, the needle rests in the central position - again supporting the 'battery fully charged' scenario.
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Also had an issue with a Wesco. After a complete charge to 12v, dropping rapidly to 10-11v. Changing it for a decent AGM cured that.
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Thanks morris. Personally I think Westcos are garbage. I do have another AGM battery which has worked well in the past. I keep it charged and in good shape so I think I'll put that on and see what happens. I've never seen an intermittent problem with a battery before, let alone the previous three - really is bizarre.
Curiously, when I was pulling my hair out over charging and electrical issues before, it turned out it was the battery. My advice was to always blame the battery first - not following my own advice, eh, bad show!
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....I guess what you're all saying is that if the battery is fully charged, the ammeter will show a discharge as the regulator is detecting a fully charged battery and won't put charge into it. Only when the battery becomes sufficiently low will the regulator kick in and show a charge.
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Assuming the engine is running and lights on, that doesn't sound right. My understanding is that the reg detects a lack of charge level, so will then will allow the genny to charge the battery showing ' + charge' on the ammeter, and when fully charged the reg will shut down and the ammeter will return to '0', then when you pull up at the lights or whatever, the lights cause a '-/ discharge' and when the lights go green, and you roar away *smile*, the ammeter should show '+/ charge ' until the battery is charged and meter drops to '0' and the cycle continues......
When the battery is fully charged, all your electrical requirements are effectively running from the generator,
hence the floating 'discharge/ '0' /charge'.
I found a really good Lucas mechanical reg. tutorial online a while ago that helps understand the principle, but is too large to attach- but doesn't explain DVR2 *conf*
I agree with kiwigf that maybe check your wiring (again?)
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Hi Wortluck,
Here's a rundown that may help...
The dynamo makes a VERY small amount of electricity when spinning if the "F" wire is not connected. When the "F" wire is connected, on a normal regulator setup, the "F" wire gets power from (via the regulator) the "D" wire.
The connectors at the dynamo end are not great, and rely upon the wiring being passed through the small ferrules, and bent back along the full length of the ferrule, which is tapered. When the ferrule is pushed into the hole in the dynamo, it locks. I had problems here, as well as a failed regulator.
So if the "F" wire is loose anywhere, (the green wire), the dynamo gets no field current, and no output results. The current flowing through this wire is not a lot, about 2 amps max on a 6V system. The original Lucas regulator switches this on and off RAPIDLY, and modern electronic regulators do the same. The "mark/space" ratio of this signal (how long it is on, compared to how long it is off) controls the dynamo output. Long "ons" and short "offs" result in the dynamo giving a high output, and vice versa.
The first thing to do is check the output of the dynamo, using a headlight bulb. A 12V bulb on a 6V system, and a 24V bulb on a 12 volt system. You join the "F" and "D" wires together, having removed them from the regulator. Individually insulate the REGULATOR "F" and "D" connections to prevent accidental connections while testing. Start the bike and run at a fast tickover, THEN connect the bulb between the joined "F" and "D" wires, and earth. The bulb should light, and quite brightly. Do not do this for long, stop the engine, because you are now giving the field coil of the dynamo more than it is used to, or wants... If this test fails, repeat at the dynamo itself. If OK, the wiring is faulty. If no good, then I am afraid the dynamo is dead *angry*
The reason for not connecting the bulb before starting the engine is that it is a non-linear resistance. When off, it is very low, and "steals" the meagre amount of electricity that the dynamo is making, meaning that the field coil does not get energised. If you do connect the bulb before starting, you will find that it does not glow, and as you increase the revs, it will suddenly come on very bright, and could even burn out. (As the bulb warms up, its resistance increases, the demands it places on the dynamo reduce and this allows the field to get current, so the dynamo starts to produce a high output).
If the bulb reliably glows when connected, (and it will probably glow dim, even at tickover), the next test is done with another wire which is joined to the already joined "F" and "D" wires, and, with the engine already running at a fast tickover, put the other end of this wire onto the "A" terminal of the regulator. (Which must still have it's "normal" wire connected, and you now have "F", "D", and "A" all joined). You should then see a charge on the ammeter. Don't do this for long, and disconnect the wire to the "A" terminal BEFORE stopping the engine.
Start the engine and leave it running at TICKOVER with a bulb connected as above (and glowing dimly), and start pulling the wiring around. At this point, you may wish to have the seat off, and the headlight out... Again, don't do this for too long, although at tickover, the dynamo is getting almost its full rated field current. So it is getting "kicked" not killed...! If you don't find any loose connections, stop the engine and reconnect everything normally. If it does not now charge, it looks like the regulator.
Now... Interpreting what the ammeter is telling you. Electricity flows through it in both directions, but not at once! If electricity is flowing from the battery, towards the bike's electrical system, (lights) the ammeter will show a discharge. If the electricity flows from the system (dynamo) towards the battery, the ammeter shows a charge. And if everything is working normally, the dynamo makes just the right amount to run the lights, plus some for the battery, a small amount if a charge is needed, and "next door to nothing" if the battery is fully charged.
The dynamo regulator responds very quickly to load changes. It works on voltage, and wants to see a certain voltage on the system. If that voltage is low (battery being drained by the lights) the regulator instructs the dynamo to generate more electricity. It does this by supplying more power to the dynamo "F" connection. So it won't wait for the lights to produce a discharge for a while, and then decide to charge the battery, it will immediately sense that the lights are taking power (and dropping the system voltage), and "up" it's output.
If you are seeing a discharge with the lights on, that stays that way for a while at a fast engine speed, and then suddenly see a small charge, the charging system has an intermittent fault. What has happened here is that the charging system has failed, the battery has started to run down, and suddenly the charging system has sprung back into life, detected a low battery voltage, and pumped in some charge. The system is sensitive, and will react to less than 1/10 of a volt.
If (with the engine above tickover) you see a discharge with the lights on, and don't see a charge when they are off, the charging system has failed!
If all is working well, run at a "50mph in top" engine speed with the lights off. There may be a small charge. If you "whack" on the headlight, you will see a momentary discharge, and the needle will rapidly climb back up to the middle, if not go slightly into the charge side. This can be seen because when the bulb is off, it is cold, and has a very low resistance. At the instance of "switch on", it totally overloads the electrical system, (for a few thousands of a second, that bulb is possibly demanding 150 watts!!!) and although the regulator and dynamo have responded, they can't keep up. As the bulb warms up, the overload disappears, and all is well.
Dynamos.... Clean commutators, decent brushes (check that the copper "pigtails" are not loose in the carbon brush) and check all connections.
Regulators. Original Lucas, clean and adjust as per service instructions/Haynes manuals. Electronic regulators. Black art. If dead, replace!
Well, that was a "war and peace" of the charging system, hope it helps, I am gonna shut up now!
Regards,
Stan.
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epic *eek*
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Another thunk. DVR2's are supplied either + or - earth. Would you have inadvertently flashed the dynamo to the other polarity causing the DVR2 to expire?
Cheers
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Stanwhite, fantastically useful post. Well done!
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Lost charging on the A10 recently. Light bulb test was OK, elderly 1st gen DVR2 had expired. Curiously, dynamo was then wrong polarity. Had to flash it back. Probably me fiddling with it... All OK now.
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Another thunk. DVR2's are supplied either + or - earth. Would you have inadvertently flashed the dynamo to the other polarity causing the DVR2 to expire?
Cheers
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If the DVR2 is not protected against a dynamo with wrong polarity it would be a very poor design! Is it really that susceptible to being damaged by that?
I would have expected the DVR2 to “ignore” any voltage of the wrong polarity coming from the armature and hence not supply any current to the field coil but who knows *dunno*
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Jeez stanwhite :o Think I'll have four more beers and go kick it over to see what happens. At worst, my blurry eyes will see the ammeter needle move a bit which will probably be good enough for me.
Seriously, thanks for your time and effort!!! *smile*
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For a concise description of how the DVR2 works why not visit Dynamo Regulators Ltd, the DVR2 manufacturers website. The very first item on our Q & A page http://www.dynamoregulators.com/faq.php
A reversed polarised dynamo will just not start up with a DVR2. The regulator will not be damaged. The DVR2 product datasheet makes this clear http://www.dynamoregulators.com/documents/dvr2-data.pdf
top of p2.
Wortluck, it is pretty unusual for one of our regulators to work for a while, then not, then start up again. Sounds more like a poor connection issue to me, or dirty commutator perhaps. By all means contact me directly. Happy to test your DVR2 to rule a problem with it in or out.
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Glad to have helped. Electrics is my game. A10s are not, so no doubt, I am gonna bend someone's ear sometime *smile*
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Thanks Mike and everyone.
I did clean the commutator with meths and it was quite oily. Have checked all wires. I think I'll replace the battery and see what happens as the previous Westcos' intermittent faults caused havoc with the charging and electrics as a whole. You'll probably find my rant elsewhere on the forum about lights coming on after a 10 second delay; ammeter readings all over the place, etc, etc. If it does turn out to be the battery again, I'm going to throw the bloody thing very hard at something very hard. *pull hair out*
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Poor battery... *smile*
But don't dismiss it as dead, see how this fits: (25 watt headlamp, 6 watt tail, 6 watt pilot, 6V system. For a 12V system, the times may almost double for a 5 ampere hour battery).
If the lights work OK, and can do so for some time with the engine stopped, (sidelights only for over two hours, headlamp/tail light for nearly an hour, assuming a 5 ampere hour battery) this tells you two things:
1) The battery was fully charged. (It won't be now!)
2) It is in good condition.
If you get a charge showing with the engine running this is quite informative too!
1) The charge system is doing something, but MAY be out of control, see 3) below.
2) if a moderate charge that slowly reduces over time (no lights, long run), the battery is most likely OK, needed a charge, and has now got most of what it needs.
3) Higher charge that does not reduce, then providing the charge system is working normally, and bulbs don't keep blowing, the battery most likely has one bad cell. If you get a high charge rate all the time with no lights, check the voltage, as this COULD be a failed regulator. If you are out somewhere and you notice this, disconnect the "F" and "D" wires from the regulator and ride home... Disconnecting will give the battery, dynamo and lights a chance!
Of course, turning the lights on, (engine off), and "rattling" the battery will possibly show any internal breaks. And if it does, then with my blessing, find something hard to throw it hard at! *yeah*
Cheers,
Stan.
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Had a good old fiddle about tonight and it looks like a loose (yellow wire) connection on the dynamo. Took the cover off and started to gently wiggle the wires, nothing at first then a proper charge with lights on and off. Moved the wire around a bit and the charge disappeared, found out the yellow wire had popped out. Put it back and pressed it in with a screwdriver and, hey presto, charge again.
Cleaned the brushes and commutator again with meths just to be sure. Any suggestions on how to achieve a tighter fit for the yellow wire?
Prize goes to all those who suggested checking wiring and to stanwhite for his jawdropping analysis of the electrics - Full Marks.
As always, thanks to those who give their time to helping dotards like me *respect*
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Real glad you got it fixed! *smile*
Rotten little ferrules... That is what caught me out! *angry*
Cut back the insulation on the wires, and have enough clean strands to fold back around the outside of the ferrule, all the way back to the outer end, and then some... Fold it back into the open end of the ferrule, 1/8 inch should be enough.
This has three effects:
1) A good clean connection, whose diameter is a little more than just a loose ferrule stuffed in the dynamo hole. That should make it a tight fit. As a result of the slightly increased diameter due to the strands on the outside, the ferrule won't go in so far.
2) the "wrapping" over on the outer end of the last 1/8 inch of the strands slightly lengthens the ferrule.
3) The ferrule stays in place the next time you remove it... (And you will, some time *lol* )
As a result of the lengthening effects of doing the wire in this way, the paxolin ferrule retaining plate (a b****r to replace, or is it just me?) bears down on the ferrule, ensuring a good connection.
Cheers,
Stan.
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Paxolin ferrule *????* :o - holy s**t Stan *eek*, you know your stuff - more thanks!!
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Know my stuff? I know electrics, but my A10 is the first Brit bike I have had in 42 years, and I am learning the hard way! *smile*
Just tried something new... And managed to get a half amp charge at a slow tickover. Clever electronics. Not clever enough, unreliable, and there is a lot of development to do. Probably not gonna ride it in the dark anyway! *grins*
Glad it has worked out for you.
Cheers,
Stan.
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Cheers Stan. Electrics are not my thing but I can follow logical steps reasonably well. For me, once I've seen something done, I can usually replicate it, but it's easier if I see it. This is my first Brit bike too, so I'm learning exponentially.
Great to get the bike fixed, I can't stand it being off the road. Bikes are for riding, not sitting in garages.
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Been out on mine tonight, and at 40mph, headlight on, it is charging slightly, so I am happy with that.
Went down some country lanes, and was amazed at just how good the lights are (original pre-focus headlamp bulb, 6V). Very bright!
But... I have been through all the wiring, replacing most of the connectors, and a lot of them were "not good"...!
Not likely to go 12V, H4, or LED. It works!
Cheers,
Stan.
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Been out on mine tonight, and at 40mph, headlight on, it is charging slightly, so I am happy with that.
Went down some country lanes, and was amazed at just how good the lights are (original pre-focus headlamp bulb, 6V). Very bright!
I'm still using a 6v filament headlight, LED rear light. I found some 45/40w Lucas bulbs on eBay that are good. I have a new headlamp reflector, that helps. I also have a new loom with wired earth's.
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6v for me too. Want to stay as close to the original as possible. If I wanted electronic ignition, 12v electrics, disc brakes, etc, etc, I'd have bought a japanese bike. The only things not of original spec on mine are the horn, regulator, and battery/strap. Even the casing screws are cheeseheads. These, of course, are the things that drive me nuts!
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Even the casing screws are cheeseheads.
I think you'll find they are Fillister Head screws ;)
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Wot's the difference Greybeard old chap *smile*
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Wot's the difference Greybeard old chap *smile*
The correct ones have that curved top. Cheesehead have a flat top. I was only able to get a mixture of Cheesehead and Fillister head screws when I was restoring my engine. Glad you don't have Allen screws! :)
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Genuinely didn't know they should have a curved top (Fillister) - certainly news to me. When I was restoring my bike, I asked the fella who was helping me with the engine to get the right screws, and he got cheesehead (flat top). These were supplied to him by a specialist BSA outlet - hmmmm. *conf2*
Hate Allen screws, just seem so out of place on our machines. That said, I do have one holding on the dynamo cover. Will replace as soon as I find a suitable fastener (is this Fillister too?).
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Hate Allen screws, just seem so out of place on our machines. That said, I do have one holding on the dynamo cover. Will replace as soon as I find a suitable fastener (is this Fillister too?).
My dynamo cover is held on by a small cheesehead screw. I reckon that is probably correct.
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Hate Allen screws, just seem so out of place on our machines. That said, I do have one holding on the dynamo cover. Will replace as soon as I find a suitable fastener (is this Fillister too?).
My dynamo cover is held on by a small cheesehead screw. I reckon that is probably correct.
Allen's make life easier, but they do stick out on old bikes.
I really dislike how they always collect water, first thing on a chrome bike to rust (and gall).
Lee
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Not really keen on Philips screws either, especially the 'combined' slotted/Philips. I must admit, that I do have a few of these on the bike too (cutout and horn/dip beam switches plus rear light lens screws), but I'm always looking for 'period' replacements without spending too much time on it. Sorry coater87, just can't abide Allen's on vintage machines - seems wrong somehow.
Need to be careful, going off topic *whistle*
Rest day today - feeling knackered after yesterdays 160m ride :!