Morris Minor Owners Club

Hello folks,
About a year ago, I had problems with the battery not charging. It turned out to be the control box, which I replaced and everything was fine. Now, a year later, I have the same problem. I suspect the regulator contacts aren't operating - I can't see/hear any movement in them when I rev the engine and they look a bit blackened. Is it worth trying to clean them before fitting another control box - or are these new ones a bit iffy, like some other modern-day new parts can be?

Your thoughts appreciated.

Cheers,

Pete

I bought a new one and it didnt charge, I carefully screwed out the point and cleaned it and put it back in and it started charging! Next new one I got there is now a leaflet in it to clean the points before use!

Have you had a look at your dynamo as well, when the brushes get worn down they stop charging too.

As above - suspect worn brushes in the dynamo as the most likely cause.

No, dynamo is fine - I checked its output. I will give the points a clean and see if that makes a difference.

How did you check it's output?

Bridged the terminals and used a test bulb............nice and bright with little revving required.

That's not in any way a realistic test! A real test will involve, yes - joining the terminals, switching on the headlights and heater - revving up and measuring the battery volts.... If 14 + volts then the dynamo is indeed fine !

Hello Roy. By bridging the terminals and then measuring the voltage at the battery, you are bypassing the control box? Is that your thinking?

Exactly - full power!

Here is a useful PDF for testing and fault finding dynamos and car electrics.
https://www.google.co.uk/search?q=lucas ... ent=safari

Well, it turned out to be the control box, as I had suspected. Put a new one in and all is well.
However, not too happy that the failed one lasted only a year - the regulator points had such a pimple on it that it couldn't break the circuit.
Has anyone else had early failure of one of these new units?
Cheers,
Pete

Like any of these 'new' parts - probably made in a hut in a far away place.... Get a good 'old' Control Box and it will likely last 'for ever'. It is worth checking that whatever box you use is correctly set - and not wildly overcharging - which would 'do in' the points quite quickly......

They can go out of adjustment so I'd suggest checking with a tester every couple of months or so. Mine was overcharging to the point the battery boiled and spit out acid everywhere. About 1/8 of a turn backwards (and a bit of paint on the screw to keep it from moving) and everything's fine again.