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B400 voltage

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Old 05-06-19, 05:31 PM
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Default B400 voltage

I'd measured the voltage with a modern meter at 3000 rpm. It is above 15V. Modern cars do not exceed 14,4 V. Something to change?
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Old 07-06-19, 02:45 PM
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When I observed the voltage, I got a little scared. I could see more than 16V and a small adapter in the cigarette lighter with a voltage indicator (China crap) was killed. Is LUCAS RF91 L33 the right control box for C45-PV? As a first aid I lowered the voltage by adjusting the corresponding screw to avoid further damage.
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Old 10-06-19, 02:16 PM
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I think you may also have posted on the Yahoo forum, in which you say that you have 10 to 20 amps going somewhere. Also that you have a low acid level in the battery.

I presume the 10 to 20 amps is going into the battery

If so it seems to me that you may have two problems. A duff battery and a maladjusted regulator.

Changing the battery is easy, changing the regulator is relatively easy but isn't really the solution as the new regulator should be set up on the car, even though it's apparently new out of the box. It's a bit like buying a woodworking chisel - it might be brand new but it will still need sharpening. In this case the regulator needs to be tweaked to match your Dynamo and battery, both of which have their individual characteristics.

If you know somebody skilled in the art of setting up the Lucas regulator get them to do it. They'll make it look easy, which it isn't.

But I think you're in Germany, if so it seems unlikely that you will be able to find that particular talent. I can't immediately think of anybody in the uk either, now, with that particular skill. No doubt they exist, but finding them would be the problem

So what I suggest you do is to secure a copy of a workshop manual for a contemporary British car, a Haynes manual for a Morris Minor perhaps, and follow its instructions as well as you can. If you let me have an email address I can scan the relevant pages from that manual and email them to you. The only really, really, difficult bit is "it is vital that the adjustment is made within 30 seconds of starting the engine". The easy bit suggests that if all else fails then change the unit. But then you should still set up the "new" one

But before you start on all this do just check that all the screws securing the wiring to and from the regulator unit are tight. Copper creeps over time when under pressure and you may find that some wires are now virtually open circuit.

Good luck
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Old 10-06-19, 03:39 PM
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Quote:
Originally Posted by PEU186F View Post
...... Dynamo and battery, both of which have their individual characteristics.
That's the challenge. Often there is a hint that regulator and dynamo must be compatible.

Quote:
Originally Posted by PEU186F View Post
If you know somebody skilled in the art of setting up the Lucas regulator get them to do it. They'll make it look easy, which it isn't.

But I think you're in Germany, if so it seems unlikely that you will be able to find that particular talent.
I'd found one for my MG but he was out of talent and a little bit fraudy.

Quote:
Originally Posted by PEU186F View Post
So what I suggest you do is to secure a copy of a workshop manual for a contemporary British car, a Haynes manual for a Morris Minor perhaps, and follow its instructions as well as you can.
I have manuals for MM and MG - but both show different voltage values for some tests. E.g. 15.9 to 16.5 for MM and 15.6 to 16.2 V at 30C for MG.

Because it is a range it will be approach - but knowing the particular values for the existing box would give a better feeling.


Quote:
Originally Posted by PEU186F View Post

But before you start on all this do just check that all the screws securing the wiring to and from the regulator unit are tight. Copper creeps over time when under pressure and you may find that some wires are now virtually open circuit.
That's what I've done before but I will repeat that step for sure.
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Old 14-06-19, 11:44 AM
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Quote:
That's the challenge. Often there is a hint that regulator and dynamo must be compatible.
I understand that different manufacturers, e.g. Lucas and Bosch, used different principles to regulate the output of the Dynamo, so neither the regulator or the Dynamo are compatible across the manufacturers. But I am fairly certain that any Lucas built regulator will be compatible with any Lucas Dynamo as the dynamos always work on the same basic principles. With the possible exception of Rolls Royce / Bentley who occasionally dictated their own views on how things should be done
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