Another Control Box!

[myoldjalopy]

Previous posts have queried the quality of the available control boxes, with one well-known individual opining that they are now made 'in a tin hut in a far away place'.
I have had to fit three in the last five years or so which, in the 'good old days' would have been unheard of. In my experience, the regulator points burn out, leaving a powdering of black dust around the points which themselves can no longer open and close correctly due to a large 'pip' forming on one of the contact faces..
The books mention cleaning them with fine emery or carborundum paper every 12,000 miles but I am wondering if more frequent attention is needed these days to avoid this problem?

[RobThomas]

I opened up one of those NEW ones. Scary! It looked like it was thrown together in a hurry by somebody who had a very tight schedule. Even Joe Lucas would have been embarrassed by it.

Weren't the Lucas ones fitted with terminals made of/with Silver for the contacts?

[geoberni]

Why have you changed 3 in 5 years?
What sort of failures were they?
How many miles, or hours of use, is that between each one?
Were they 'new' ones or old 2nd hand original units?

I don't know what the MTBF (sorry technical jargon - Mean Time Between Failures) is supposed to be, but there are set-up adjusting instructions in the manual.
So I'm the newbie at all this and haven't needed to do any Control Box adjustments yet, but I'd certainly try before replacing one.

Sorry if you've tried adjusting them before replacing.

[oliver90owner]

Problematic, if you want to keep things original. But that regular regulator replacemnt rate would soon finance a change to alternator!

RAB

[myoldjalopy]

geoberni:
Why have you changed 3 in 5 years?
Because they have failed - specifically, not enabling charging the battery
What sort of failures were they?
As stated in my original post - the regulator points burn out and cannot separate effectively
How many miles, or hours of use, is that between each one?
Between 3,000-5,000 miles, at a guess
Were they 'new' ones or old 2nd hand original units?
'New'
Does that help you answer my original question?

[geoberni]

geoberni:

Does that help you answer my original question?

Well it does give me is an indication as to if you have tried to ensure they are set up correctly and you haven't just been chucking them rather than doing so.

I was trying to eliminate other reasons the contacts are burning, rather than just jump to the conclusion that the control units are at fault. Perhaps I'm wrong, but I get the feeling you didn't like my questions so I'll just leave you to it.

[myoldjalopy]

Indeed, these units can be adjusted, although the books mention that this is not normally required. I think the point is that no adjustment was necessary to the new units as they neither overcharged or undercharged when fitted and went on for a few thousand miles. Once the points burn out, its not really a case of adjustment, unless you file down the points and re-set the gap and I'm not sure how successful that would be when they are badly burnt.......So, to me, the issue is whether anything can be done to stop the points burning out by more regular cleaning

[geoberni]

What's your electrical load like?
The original book says that they don't normally require adjustment, but that was an era long ago when people didn't have any extra electrical load.
Cutting a very long and technical story short, the Regulator controls the electrical generation circuitry by opening and closing the contacts. 1 set is used at low speed to stop the battery trying to turn the dynamo like a motor (a dynamo is basically a DC Motor being used in reverse).
The 2nd set is used when the voltage is too high.
So this opening and closing of the contacts can take place several times a second as you vary the engine speed.

Pitting of the contacts is caused by the opening and closing of the contacts with current flowing through them, so the greater the amount of electrical load, the more likely the contacts will burn.
While the dynamo might be capable of delivering 20+amps, the regulator isn't going to appreciate having that load being switched on/off rapidly.

Many people think it's the Dynamo that is going to be the problem when they add extra electrical items, it's actually the capabilities of the overall system they need to think of, including the regulator.

For what you have said, I think your problem is not the Regulators, it's what you're running off the system that is driving them to an early grave, even if it's a fault somewhere that is causing too much current to be drawn. Possibly even a weak battery that is constantly pulling a lot of juice to keep it charged.
That's one of the reasons I'm going to be fitting my dynamo system with an Ammeter.

If you want to understand more about the workings of the dynamo system, there's a good blog here, just keep in mind it's written about a 6v system used on motorbikes, http://matchlessclueless.com/electrical ... regulator/

[myoldjalopy]

Load is bog standard, nothing additional. So a bit of a mystery at present. Will keep a closer eye on things this time round.

[geoberni]

I'm a bit suspicious of the battery then. What's it's condition?

if you've not got one wired in, can you get hold of an ammeter and see what sort of current iit's taking immediately after you've started the car?

I'd expect about 5-6 Amps charging if the battery is in reasonable condition.

if you're not confident doing such checks is there someone who can do it for you?

It may be that you're having a run of 'bad luck', but with so many Minors still out there running Dynamos, it's hard to imaging the Regulators are really that bad.

[ManyMinors]

I think that regulators like so many other things, are generally reliable but the new replacements available seem to be complete rubbish with a very short life expectancy. I have had a couple of failures too

[myoldjalopy]

Well, there you go then! Anyway, not to worry, as the old girl passed her MOT today with no advisories

[ManyMinors]

I fear that the best answer if you want to retain the original dynamo system (which generally works fine for me) might be to get an original Lucas control box rebuilt by a specialist who undertakes such work. A friend had this done with his car (not a Morris Minor but has the same control box) a few years ago and all has been fine.
One of our Minors has been converted to an alternator and that seems to have been made to the same standard as the new control boxes unfortunately! It is a great shame that our good, simple, reliable cars often seem to suffer from problems caused by poor quality new parts.
The MMOC has, for years, talked about getting new good quality parts produced but.......????

PS well done with the MOT

[RobThomas]

Not hard to rebuild one but the difficulty is finding points. Would people be prepared to pay for them? Points would cost maybe £30 against £25 for a complete cheapo Chinese copy.

[oliver90owner]

£30 for the proper kit versus £25 for a cheap and nasty replacemrnt?

Seems very much like "buy cheap, buy twice" to me!

[RobThomas]

I'm lucky in that I've been given about 30 pages of A4 on rebuilding the Lucas regulators, on the understanding that I don't give copies away. Lots of useful info and some great diagrams. Pity I'm not allowed to post it up.
Of interest was the fact that the Reg from a Landrover or any other vehicle is not ideally suited to a morris. The number of coils nearest the outer edge of the car differes between cars, hence the different 8-digit ref number on the back of the Reg box.


http://www.vintagemecha-tronics.com/ind ... nformation ........if you have a spare £150.

http://www.dynamoregulatorconversions.com/gallery.php .........for a few quid more.

[RobThomas]

https://www.picclickimg.com/00/s/MTIwMF ... nd-_57.jpg

4 coils

http://images.lotuselan.net/lel/49621/1 ... -front.jpg

2 coils

[les]

Didn't realise you had links with MI5 Rob, even more surprised they had info on the Lucas control box!
I'm sure the document will eventually be released under the 50 year rule.

[myoldjalopy]

As an addendum to this post, note the comments made about the 'Lucas style' copies on this company's website: http://www.dynamoregulatorconversions.c ... lators.php
Clearly, these copies are not up to the quality and reliability of the original old ones, which my experience (and that of others) confirms.....