Morris Minor Owners Club

I've recently had a problem with my dynamo, which I've replaced with another but have started thinking about an alternator. I thought there might have been a 'sticky' on the modification. Can someone post the wiring alterations that are required for this change please? As I may consider this in the future. PLEASE IGNORE THIS POST------THERE IS A STICKY!!!
However the size/rating of the main cable would be useful.

Mine came with the required cable, one thick and one thin to the starter switch, and the other to the ignition light

As long as you use a Lucas 16 or 17 or 18 ACR - the existing cable is heavy enough. The critical thing is the amount of current the car uses - that determines how much the generator produces. So if nothing else changes in your car - an alternator will churn out the same current as your dynamo did before... And of course - the car needs to be running negative earth...

one of the best mods you can do ,even very later moggies had alternators

The table below shows the outputs for the Lucas ACR alternator range and the cable sizes required to take the full output current. This will be required from the alternator up to either the starter solenoid or pull switch, as that will at times take the full output.

One advantage of the ACR range is that it has two main output terminals (2 x Lucar 35A), so instead of one large single cable, you can run 2 smaller cables, one from each alernator terminal, and connect them both to the solenoid/pull switch. We have used 2 x 65/0.3mm cables for our ACR23, which is much easier to terminate and route than a single 120/0.3mm.
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A standard car with no power greedy extras - just needs the standard wire - it's perfectly adequqate. Even running in to a 'flat' battery - an alternator actually pushes less current into the battery (but for a longer time of course) than a dynamo.

Thanks for the tables and information Richard, it will be a handy reference.

Will someone confirm the obvious, please. The alternators have built in regulators.
I've had alternators on vintage machines that had external regulators.
thanks
David

with very few exceptions yes built into the alternator

For Lucas alternators the 'R' indicates an integral regulator, so 15AC needs an external regulator and 15ACR has it built-in. Virtually everything around today has the regulator integral with the alternator.