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Lucas E3L dynamo woes


Goat

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Havent done that yet.

I did that to the dynamo pre rebuild and it was cranking out a healthy 20v at fast tickover.

Could it be the field coil thats chooched? IDK. I thought 9v on the field would be enough to make all the magnetism it needs...

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Just went and did that. I get 23v output if i put 12v to the field coil...

 

I connected it all up with battery and regulator and i dont get anything above battery voltage out. 

I have no idea whats wrong :(

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Thats why i'm confused!

To test them, you connect output to field, then take the voltage between that and ground. This is the where i get 9v.

The regulator is meant to pump voltage into the field coil to increase the output. When you bridge the output to the field it does this and is kinda exponential. The more voltage to the field coil, the more voltage is output. But this seems to peak at 9. It should be 20+ volts.
Connecting field to 12v should be like the dynamo running at max juice (i believe). And yeah, when i do this i get 23v output. So its like its not exciting itself. 

If i dont connect the output to the field, it outputs like 1 or 2 volts. Which is correct, as this is only relying on the residual magnetic field in the field coil core. The idea is that this is enough to magnetic field to generate some voltage which is fed back into the field coil, to make a stronger field to generate more electricity.

But it doesnt seem to be doing this properly. It is generating. But not enough. All the guide i can find on the inter web say either it doesnt generate, it generates 1 or 2 volts, or it works. Mine isnt the first two, but its not working fully either...

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Looking at the wiring diagram for the regulator, I haven't wired it up properly when i tested it. 

Will have a crack on wednesday and see if that helps. Wonder if the regulator has been damaged (either by me, or by previous owner).

 

However, the fact it still doesnt generate enough voltage to require regulation has me scratching my head. A bit too late now to go and fire it up.

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I am at work with not much to do but search the webz, does this help?

The voltage regulator sends power out through the field terminal that goes to the generator and that’s how the generator comes to life. So for test purposes, what you want to do, is with the wires still in place on your voltage regulator, get a jumper lead connected to a power source. Wiggle that on in until making contact with the field terminal. Now we’re sending full field current to the generator. When we do that, we’re doing the voltage regulator’s job. When we do the voltage regulator’s job, if the generator comes to life, the voltage regulator is probably our problem. However, with the wires in place, if we put full current right here with that wire that goes from the field to the generator and she still won’t come to life, chances are strong the problem is in the wiring between here and the generator.

https://mossmotors.com/how-to-test-voltage-regulator

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@terry nope, you should have seen the barriy-d wiring on this thing. It had some "fancy" electronic ignition, which was blown. Replaced that. Still ran like a turd and was impossible to start.
Tracked down an original magneto. Now its a 1 kick bike. Just wish the charging worked.

@ kicker Interesting, i was just bridging the two terminals and measuring that voltage...
Following the steps 5, 6 and 7 here: https://www.matchlessclueless.com/electrical/lucas/testing-lucas-dynamo/

Will try connecting up the fancy regulator as per its instructions and see if that works. Requires rewiring of the dynamo weirdly, as its currently setup as per most internet instructions. And it motors in the correct direction when you put 12v on it. Again, this is what internet says is a good setup...
That write up above implies that it needs battery voltage to get up to full generation. Other sources seem to think it can work fine without a battery. (My harley dynamo and regulator produces a steady 13.8v at idle without a battery)

Theres nothing to them, so i cant really figure out whats gone wrong.

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Small update,

Wired it up as per regulator instructions. Still nothing. 99% sure its not the regulator. As it doesn't even produce max power when running unregulated (connecting Field And Armature output). 
Am pretty sure the regulator is poked anyway. (like everything else electronic on this bike).


Might try throwing more money at it with a new field coil, as that's the only thing I haven't replaced.
New brushes, brush plate, armature, bearings. Literally the only thing I haven't replaced is the field coil. Whats another hundred bux eh. :unsure:

Will dig out my old points style Harley regulator and see if I can use this to regulate.

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Another pointless update.

Still been playing with this. Noticed resistance across brushes was quite high, and checked that brushes were seating properly (they weren't). Gave them a quick sand to get better contact and it now has about 2.5 ohms across the brushes all around the armature. So that's promising.

Tried running it bridging F and D. Starts at about 12v then drops down to 6v or so. Doesn't seem to increase as revs increase. When wired like this (unregulated) Its meant to rise quickly then be pinned to max output (over 20v) at around 1800 rpm.

What confuses me, is if I disconnect everything from the mag, run the bike, I get around 2v from the output, which is exactly what its meant to do, and if I connect 12v straight to the field the output shoots up to 23v!. Again, perfect!

So not sure why its not shooting up to over 20v if I connect output to the field. Its meant to go into "runaway" mode, where voltage on the coil makes more magnetism, and the extra magnetism makes more voltage. I wonder if there is something wrong with my bridging wires? Though I can't see how this could be a problem.

What really confuses me, is that it is similar behavior to before I replaced the armature. Except It would only output 1.5 odd volts with terminals bridged. But shoot to 20+ if I put 12v on the field. So its better than that, but still not where it should be. Its only half working.


Fuck I don't know. Its literally the simplest thing ever, but still doesn't work. And following every troubleshooting guide isn't helping, as my symptoms don't align with anything in the guides (voltage starts off high then drops off). Everything in the troubleshooting guides is either it works or it doesn't, not it kinda half works. No wonder Lucas has a shitty reputation.

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