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Yeah, thanks for confirming. I was really only questioning it in my mind if the logic was sound, and thinking out loud as I wrote. Since then I've given it a fair amount of thought, whilst studying the circuit diagram, and I'm happy that it's so. All connections to the regulator, are available elsewhere, simply at longer range, which I don't believe will change anything, as long as the battery is disconnected.

As for if the generator is suspect, that looks to be a pig to replace, from what I've seen. So much to be removed, just to get at that, and it would definitely have to come home. Everyone who showed it, had the whole assembly on the bench. :eek:

Please just be bad connections, or the rectifier, lol.
Mine was only on the bench because I already had it apart for different reasons .
The whole cover behind the recoil starter has to come off to get at the alt windings , and there's gears and shim washers and all sorts of potential disasters in there 馃槅馃槅so yeah , I hope its not the alt too馃榾
 

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Discussion Starter · #23 · (Edited)
Update report:

All test performed successfully, and according to plan.

Connector located, opened, didn't look bad, good in fact, but cleaned thoroughly anyway. Re-inserted several times, and retested charge performance. Little to no improvement.
Disconnect again, and measured the resistance of all three generator coils. All within spec, and all bang on equal. Phew!
Run engine, to high revs, and measure all three AC voltages, pin to pin. Well in excess of 60V at 5000 rpm, and all about equal. Not possible to say if identical, because of fluctuation of steady rpm, but all three similar, and well high enough. Double phew!
Disconnect battery, and perform all diode tests, on the rectifier, as shown in the table previously, but all away from the regulator, at the end of long wiring looms, as I suggested might be possible above. All read a tad higher than spec, which did not surprise me, with the extra wire involved, but all read in the correct region, and matched each other where they should. Also, all were the high values, when meant to be high, and the low values when meant to be low. To my mind, the diodes were all behaving perfectly, at this low test voltage, thus, most likely, confirming that the rectifier portion of the rectifier/regulator is operating within spec. Of course, you can't test how those diodes behave under the much higher AC voltages from the coils, at high rpm, but in my mind they passed this low voltage diode test perfectly well.

What the manual never mentions, is how the regulator itself can be checked. Personally I don't think it can be checked. The diagram I showed earlier, shows an array of diodes, which I assume will perform the rectification, but the regulator, unmarked, is just a mystery black box. If, whatever is in there, is failing, how can that be checked properly?

Knowing that it passed all the prescribed tests to this point, I put it back together, and performed the charge voltage test again, and confirmed something that I'd noticed last time, but was wanting to check it for sure, before reporting it fully here. When I rev up, the more I rev up, the lower the output gets. To my mind, it should go higher and higher, within controlled limits, and get to, or above, 13.5V and stay there. Indeed, since it's meant to be regulated, it should soon be at 13.5V, with just a few revs, and stay there, all the way up to 5000 rpm.

Mine did the following. Lights on high beam, at idle, 13V and slowly climbing. Revved it up, and as it ramped up to 5000 rpm, the charge voltage dropped and dropped and dropped, until it read 12.75V, which is well below spec. On letting it go back to idle, it soon climbed back to above 13V, and continued it's very slow climb. So it could charge at low revs, but was loading the battery, and causing drain, at high revs, when the coils were definitely outputting a much higher AC voltage, because I'd already checked that. So, to me, it actually looks as though it's overregulating as the output from the coils increases. Maybe this is common for whatever is inside of the mystery box, when it's beginning to fail, who knows?

Either way, that points to poor regulation, to me.

The other thing, that pointed to lack of regulation, to me, is that the lights flicker a little, at lower revs. If being regulated well, the voltage should be steady, wouldn't you think?

I realise I have to get both the rectifier and regulator, since they are in the same package, but I'm fairly sure these two outcomes point to the regulator itself, and I need a new rectifier/regulator, despite the fact that it actually passed all the tests described above, apart from the actual charge rate test itself.

Would you guys agree that it seems likely to be failing, or might there be something I've overlooked. Of course I've not checked it at the regulator itself, but if the wiring or the connector there were dodgy, my diode tests would have been way out, and they were not.

Cheers

Sutty
 

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Update report:

All test performed successfully, and according to plan.

Connector located, opened, didn't look bad, good in fact, but cleaned thoroughly anyway. Re-inserted several times, and retested charge performance. Little to no improvement.
Disconnect again, and measured the resistance of all three generator coils. All within spec, and all bang on equal. Phew!
Run engine, to high revs, and measure all three AC voltages, pin to pin. Well in excess of 60V at 5000 rpm, and all about equal. Not possible to say if identical, because of fluctuation of steady rpm, but all three similar, and well high enough. Double phew!
Disconnect battery, and perform all diode tests, on the rectifier, as shown in the table previously, but all away from the regulator, at the end of long wiring looms, as I suggested might be possible above. All read a tad higher than spec, which did not surprise me, with the extra wire involved, but all read in the correct region, and matched each other where they should. Also, all were the high values, when meant to be high, and the low values when meant to be low. To my mind, the diodes were all behaving perfectly, at this low test voltage, thus, most likely, confirming that the rectifier portion of the rectifier/regulator is operating within spec. Of course, you can't test how those diodes behave under the much higher AC voltages from the coils, at high rpm, but in my mind they passed this low voltage diode test perfectly well.

What the manual never mentions, is how the regulator itself can be checked. Personally I don't think it can be checked. The diagram I showed earlier, shows an array of diodes, which I assume will perform the rectification, but the regulator, unmarked, is just a mystery black box. If, whatever is in there, is failing, how can that be checked properly?

Knowing that it passed all the prescribed tests to this point, I put it back together, and performed the charge voltage test again, and confirmed something that I'd noticed last time, but was wanting to check it for sure, before reporting it fully here. When I rev up, the more I rev up, the lower the output gets. To my mind, it should go higher and higher, within controlled limits, and get to, or above, 13.5V and stay there. Indeed, since it's meant to be regulated, it should soon be at 13.5V, with just a few revs, and stay there, all the way up to 5000 rpm.

Mine did the following. Lights on high beam, at idle, 13V and slowly climbing. Revved it up, and as it ramped up to 5000 rpm, the charge voltage dropped and dropped and dropped, until it read 12.75V, which is well below spec. On letting it go back to idle, it soon climbed back to above 13V, and continued it's very slow climb. So it could charge at low revs, but was loading the battery, and causing drain, at high revs, when the coils were definitely outputting a much higher AC voltage, because I'd already checked that. So, to me, it actually looks as though it's overregulating as the output from the coils increases. Maybe this is common for whatever is inside of the mystery box, when it's beginning to fail, who knows?

Either way, that points to poor regulation, to me.

The other thing, that pointed to lack of regulation, to me, is that the lights flicker a little, at lower revs. If being regulated well, the voltage should be steady, wouldn't you think?

I realise I have to get both the rectifier and regulator, since they are in the same package, but I'm fairly sure these two outcomes point to the regulator itself, and I need a new rectifier/regulator, despite the fact that it actually passed all the tests described above, apart from the actual charge rate test itself.

Would you guys agree that it seems likely to be failing, or might there be something I've overlooked. Of course I've not checked it at the regulator itself, but if the wiring or the connector there were dodgy, my diode tests would have been way out, and they were not.

Cheers

Sutty
Interesting you say about the lights fluttering at low speed, I had this with mine while I was testing the charge current. The meter probe came off the battery and without the battery to smooth the reg output (you should see the output on an oscilloscope ) the lights did flutter a bit .........I have been thinking all along that its like your reg/rect is working . Voltage is low because the reg "thinks " its putting in 14.2v. At some point in the recipe the reg senses the output voltage and adjust accordingly.
The low voltage and the fluttering lights make me thing you have a poor connection between the reg and the battery . This could be in either the positive to the battery or the earth path to the neg batt terminal . I dunno if you know the engines in these things are rubber mounted and there needs to be an earth lead from engine to frame as the battery earth lead bolts to the engine by the starter motor . There is a small earth wire from the battery to the harness ....I dunno where it attaches to the frame but Id be suspicious of the connections .
It fits that a poor connection would explain both the lights and the low voltage .
I have found a few difficult faults by gently pulling on the wire your testing . I have seen all the conductors broken between the 2 crimps holding the terminal on .....worked fine till I pulled on it . Another sneaky trick is for terminals to come out the back of the plug instead of making connection .
Some digital multimeters have a smoothing option to stop the display jumping about so much .馃榾
 

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Discussion Starter · #25 ·
Thanks, well worth checking into, but I think it's going to have to come home, because I don't fancy doing that up there. Just been reading some fault finding for regulators and it says, for the same symptoms, that the regulator could be faulty, or it could be bad wiring, just as you have now explained. Could I impose upon you to go into more detail as to why you think it might be wiring as opposed to the regulator itself?

I knew the engine was on rubber mounts, but I didn't realise the implication for the requirement of a separate ground lead. It's obvious now you say it, so thanks. Thinking about this, is the starter motor ground served by this same lead, i.e. positive wiring only to the motor, and return through the engine/gearbox case and then back through the ground lead? If so, I have good strong starting, when the battery is actually charged, lol. If so, the implication being that the grounding lead for the engine is sound, wouldn't you think?

The positive from the regulator to the battery, I have nothing to go on there, other than the diode tests, which were passed, but, those are low voltage, and very low current, so it's possible an issue wouldn't show up there? Same I suppose for the negative there, if it isn't through the frame? I suppose it isn't, with it having a separate ground lead coming out of the regulator, but maybe it's cross bonded to its metal case as well, but I have no idea?

Rectifier/regulators, OEM, are pretty damned expensive, but I found a real cheap one, at 拢21, delivered to the UK. I'm almost tempted to get one, regardless of if I have a wiring fault or not. It's generic, but references LT-F250, and the connector looks right. They say, higher quality components than original OEM, but they would, wouldn't they, lol.


What do you think, get it anyway, it's cheap? I'd definitely buy it if I could just slap it in and test, but I'll have to do a bunch of disassembly just to do that. If there was no change, then test all the wiring, if it worked, wiring is fine, but the front all has to come off to do either, grrr.

Obviously I haven't even checked/cleaned the connector at the rectifier/regulator end, so those could be poor, because again, I only have the diode check to say anything about the integrity of the connections or wiring, and maybe that's not adequate load to highlight a fault?

Just going to remind myself of what's involved with taking all the front end off, just to see if it is remotely possible to do it up there.

Cheers

Sutty
 

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First thing that I thought of was grounds. I had looked at this a while ago. Cheap enough to try if you get to that point. I'm going to add some grounds to my King Quad I'm working on. The battery ground on my Harley got loose and was giving me fits. Then the bolt fell off in the middle of nowhere of course. Dead on the road. No fun.
Font Line Cable Automotive lighting Electronic device
 

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Discussion Starter · #29 ·
Ha we were typing at the same time.
Ah ha, yes, and thanks for the link. Cheap generic product, similar to what I found, but yours is in the US. 拢21 is just about what we would pay for something at about $15 anyway, just because we always get ripped off in the UK, so if I decide to get it, I'd be happy paying 拢21 anyway. Definitely cheap enough, either of them.
 

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Discussion Starter · #30 ·
I'll look in a minute but I think the starter ground is the only path from the motor to earth. You can't have to many grounds I remember my dad saying. I don't know if you could find something like this in the UK but it might be an option for you.
Thanks, that would be a good help if you could confirm that. As for the trailer, I don't have a car with a tow bar fitted, sort of. I do have a trailer, into which it fits, but it scares me, and it has no safety chain. Not entirely sure it's safe to use, but either way, my car with a tow bar is dead, and will probably not ever be going back on the road. It failed its road worthiness test due to excessive rust on the rear sills. The test engineer concluded this when he pushed his thumb through the rear sills on both sides. :) Since then it has been sitting in its garage, whilst I ponder on whether it is worth having it repaired, but it isn't.

If I have to buy a new car and a trailer, to bring it home, it will be an expensive repair. Only kidding, and I guess I need to sort something out in terms of towing and a trailer anyway, but it's not an immediate option.
 

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I get the feeling its wiring because the reg is regging and recting its just a volt to low so Im thinkin its either sensing output voltage incorrectly or you have lost a volt due to poor connection . Volt drop test is the way here , and it aint hard to loose a volt . My Ducati had 9v at the cdi .....all due to a series of old Italian electric connectors failing , and a crap designed harness .
Usually , not all the time , I find components like the reg/rect either work or they dont .....nothing in the middle . And with reg/rect every one I have seen failed has signs of excess heat .
Actually , just remembered , on Ducati site there has been a bit of discussion re charging issues and a popular mod it to drill a hole in the reg cooling fin and bolt another earth to that and back to the neg terminal .
And that reg you are looking at looks remarkably similar to one I have here but never used . Those ones are pretty common and by all accounts work well . My old LT250 fried the reg/rect and burnt out the alt windings and I wound up with two new regs somehow 馃
 

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I like McTools idea about the bolt on ground. Here's a mod done on here. And I looked and see only the ground on the starter. Could you get by with riveting some sheet metal on to cover the rust?
 

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Discussion Starter · #33 ·
Excellent guys, thank you. McTool, that makes good sense, in that they normally work or they don't. Makes even more sense, having read some posts in the mod thread that Foot0069 posted, where one guy explained that the volt drop is not linear. Drop 0.2V at the regulator, and you drop much more for the charge voltage.

No issue doing an extra earth mod, if it's required, once the front is off, that would be simple. My friend just said he's happy to go and try with me, to see if we can get the front off, easily enough, in the farm yard, though I think we need to wait for calmer, drier, warmer weather.

I just bought the cheap one anyway. It's cheaper than the petrol there and back, for another trip to attempt a different fix each time. Each trip probably costs me 拢30. Might be warm enough by the time it gets here?

As for riveting on sheet metal to the car, I doubt it's acceptable, though I don't know for sure. Couldn't give two hoots about appearance, I'm not that sort, and a lick of black paint would make it good enough anyway, but, the reason it failed, is as follows: "Severe safety issue. Required area of high structural integrity, within 300mm of seatbelt anchoring points, compromised beyond acceptable limits."

I doubt they'd accept riveting on a plate or two. The tests for road worthiness, here in the UK, required each year, are very thorough and rigorous. No one ever sits in the back, so I wouldn't care, but if it doesn't have a certificate, it cannot be driven, or at least I wouldn't drive it. No certificate, invalid insurance, etc, etc.

I know I could have a proper job done for about 拢1000, I checked a while back, but the car is worth about 拢250. :)
 

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Excellent guys, thank you. McTool, that makes good sense, in that they normally work or they don't. Makes even more sense, having read some posts in the mod thread that Foot0069 posted, where one guy explained that the volt drop is not linear. Drop 0.2V at the regulator, and you drop much more for the charge voltage.

No issue doing an extra earth mod, if it's required, once the front is off, that would be simple. My friend just said he's happy to go and try with me, to see if we can get the front off, easily enough, in the farm yard, though I think we need to wait for calmer, drier, warmer weather.

I just bought the cheap one anyway. It's cheaper than the petrol there and back, for another trip to attempt a different fix each time. Each trip probably costs me 拢30. Might be warm enough by the time it gets here?

As for riveting on sheet metal to the car, I doubt it's acceptable, though I don't know for sure. Couldn't give two hoots about appearance, I'm not that sort, and a lick of black paint would make it good enough anyway, but, the reason it failed, is as follows: "Severe safety issue. Required area of high structural integrity, within 300mm of seatbelt anchoring points, compromised beyond acceptable limits."

I doubt they'd accept riveting on a plate or two. The tests for road worthiness, here in the UK, required each year, are very thorough and rigorous. No one ever sits in the back, so I wouldn't care, but if it doesn't have a certificate, it cannot be driven, or at least I wouldn't drive it. No certificate, invalid insurance, etc, etc.

I know I could have a proper job done for about 拢1000, I checked a while back, but the car is worth about 拢250. :)
Ah only 250 quid ......so not a Capri then 馃槅
 
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