Regulator replacement

[alanworland]

Had a spot of no charging on my 52 MM, problem was an open circuit coil in the regulator.
Fitted a replacement and it appears to work well, but the standard of construction is well below the original Lucas part.
Wondered if there was an 'electronic' replacement for the original that's recommended?

Alan

[MM1949]

I recommend the regulators from CLASSIC DYNAMO & REGULATOR CONVERSIONS LTD. I replaced my lowlight with one of their regulators, it is excellent. It looks like an original. I have since purchased one for my van.

[svenedin]

Yes I second this recommendation. The chap at https://www.dynamoregulatorconversions.com is Pete Jury. I fitted one of his electronic RB106 regulators a few years ago (positive earth) and it has been faultless. You can use the original Lucas cover and it will look completely original.

Being something of a purist I wouldn’t have switched to the electronic RB106 if I could get decent parts but the currently available new stuff is junk. You can, if you hunt around, find some quite decent second hand Genuine Lucas RB106 units and even make a good one out of two if you have the time and inclination but they need to be set up correctly and so you do need the information and equipment to do that. The book "Repairing and Restoring Classic Car Components" by Peter and John Wallage has some good information on fixing the RB106 (First published 2001 ISBN 1 85960 694 6).

Stephen

[myoldjalopy]

Which current limit (amps) did you select as suitable for a Morris Minor? I have a cheap copy currently in my car which has, amazingly, been working well for the last six or seven years but I know it will fail at some point. Been through others a lot quicker than that though!

[svenedin]

I have the 22 amp model which is the one for a Lucas C40 dynamo.

20 amp model for the earlier Lucas C39.

Stephen

[geoberni]

Had a spot of no charging on my 52 MM, problem was an open circuit coil in the regulator.
Fitted a replacement and it appears to work well, but the standard of construction is well below the original Lucas part.
Wondered if there was an 'electronic' replacement for the original that's recommended?

Alan

That's very heavy gauge wire to go open circuit. If you still have it, it might be fixable. Did you check the underside, the connections under there can burn a bit like a fuse, if there's a current fault.
I got this one from an autojumble and the connection on the underside had been repaired, but not particularly well.
I soldered a short link in to repair it. Works fine now; I slaved it in and it performed well according to the Ammeter and the voltage checks I did.

20250304_173418.jpg (1.15 MiB) Viewed 6283 times

20250304_173430.jpg (1.18 MiB) Viewed 6283 times

I have an article about how to conduct a simple modification to improve the RB106, by Dr Hugo Holden in 2011. I downloaded it about 5-6 years ago but I can no longer find it anywhere to give a link to it. It was called 'RB106 Modification', but darned if I can find it anywhere now...
I'm thinking of trying the modification to see how it goes.

[Nickol]

I have had a lot of problems previously with the RB 106 regulator and its "new" replacement after market copies.

In the end I got a digital modern one which externally looks exactly the same and its is fantastic! Whereas before, the ammeter always showed a discharge with the headlights on, with the digital at anything more than tickover, it charges quite normally and also the ammeter hardly ever flickers like it used to. I know many have fitted alternators instead of the standard dynamo for reliability but my experience has shown this to be unnecessary with the digital version.

[svenedin]

I have had a lot of problems previously with the RB 106 regulator and its "new" replacement after market copies.

In the end I got a digital modern one which externally looks exactly the same and its is fantastic! Whereas before, the ammeter always showed a discharge with the headlights on, with the digital at anything more than tickover, it charges quite normally and also the ammeter hardly ever flickers like it used to. I know many have fitted alternators instead of the standard dynamo for reliability but my experience has shown this to be unnecessary with the digital version.

I completely agree. So many people dismiss the dynamo as being old and useless when the problem is actually with the RB106. They fit an alternator and then assume they were correct that the dynamo was rubbish forgetting of course that by fitting an alternator they are no longer using the RB106. It seems that people are not willing to use a manual and a multimeter to diagnose where the problem is! Dynamos are very simple but they are repairable and with basic maintenance like replacing brushes and maybe a bearing they can go on working for decades and decades. An alternator will have long ago gone in the bin. I now have 5 dynamos in my spare parts. They all work and they were all very cheap. I have enough to last beyond my lifetime!

Stephen

[svenedin]

Had a spot of no charging on my 52 MM, problem was an open circuit coil in the regulator.
Fitted a replacement and it appears to work well, but the standard of construction is well below the original Lucas part.
Wondered if there was an 'electronic' replacement for the original that's recommended?

Alan

That's very heavy gauge wire to go open circuit. If you still have it, it might be fixable. Did you check the underside, the connections under there can burn a bit like a fuse, if there's a current fault.
I got this one from an autojumble and the connection on the underside had been repaired, but not particularly well.
I soldered a short link in to repair it. Works fine now; I slaved it in and it performed well according to the Ammeter and the voltage checks I did.
20250304_173418.jpg20250304_173430.jpg

I have an article about how to conduct a simple modification to improve the RB106, by Dr Hugo Holden in 2011. I downloaded it about 5-6 years ago but I can no longer find it anywhere to give a link to it. It was called 'RB106 Modification', but darned if I can find it anywhere now...
I'm thinking of trying the modification to see how it goes.

Berni,

Article by Dr Hugo Holden 2011 on how to repair the RB106 and make a simple modification with a "snubber diode" to protect the contact breaker.

https://www.lrsoc.com/forum/forum_files ... _RB106.pdf

Stephen

[Mervin]

"I now have 5 dynamos in my spare parts."
So do I Stephen. I'm glad it's not only me that likes to collect "stuff". All work perfectly with new parts as required, e.g. commutator end bush, pulley end bearing, brushes etc..

[alanworland]

Apologies for my lack of responses!
Thanks for your replies guys I will check out the links.
Geoberni, I replaced it a while ago (3/4years?) and although the coil is wound with a heavy gauge 'wire' I seem to remember within one of those coils was another winding using a much thinner gauge, it was this that went open circuit.

Alan

[geoberni]

Apologies for my lack of responses!
Thanks for your replies guys I will check out the links.
Geoberni, I replaced it a while ago (3/4years?) and although the coil is wound with a heavy gauge 'wire' I seem to remember within one of those coils was another winding using a much thinner gauge, it was this that went open circuit.

Alan

Hi, just back from 12 days away on holiday myself.
You're right, I'd forgotten the Shunt windings are there, thin wires not usually noticed as they are under the thick Series windings.

RB106.JPG (27.71 KiB) Viewed 2225 times

[geoberni]

Berni,

Article by Dr Hugo Holden 2011 on how to repair the RB106 and make a simple modification with a "snubber diode" to protect the contact breaker.

https://www.lrsoc.com/forum/forum_files ... _RB106.pdf

Stephen

Hi Stephen
I've seen that one too, but it's not the one I was speaking about.
It used to be on a site http://www.worldphaco.net/uploads/SAVIN ... RB1061.pdf, but that is now defunct.

However, I've now found it again on the MGA Guru website, where they link to the "Web.Archive" site:
https://web.archive.org/web/20160716130 ... RB1061.pdf

Berni