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Alternator rebuilding (regulators)


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I have 4 Lucas ACR alternators I want to rebuild.

But 2 alternators of them have regulators with 2 wires and the other 2 have the regulators with 4 wires.


Found the rebuild kits in europe.

But my main question is, can you switch from 4 wire regulator to 2 ? 


And what is the difference between the 2 and 4 wire regulators




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It's not easy to find good information on this, but here is some pure speculation:

The Four wire may have an explicit ground wire, while the two wire uses the case for the ground connection.

There are two ways for the regulator to sense the system voltage.  In "remote sense", there is an explicit wire that connects directly to the battery.  In "machine sense", the regulator senses battery voltage from the same wire that charges the battery.

This might be hogwash.


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I can say with confidence that I don't know the answer to this. But the little I do know would make me cautious about interchanging the regulators between 2, 3 and 4 wire types. An electronics whizz would be able to say for sure, but I'm not!

* One question is whether all 14TR regulators are 'the same' inside? No. The configurations differ in terms of transistors, capacitors and diodes so may or may not be functionally equivalent.

• Another difference is whether a surge protection diode is fitted to that a particular alternator or not. Some ACRs were, others weren't.

• Then there's external differences in connections depending on whether the alternator is battery or machine sensed. i.e whether there is a separate 'B+' terminal externally.

Given that 14TR regulators are readily available at under a tenner I'd be most inclined, for myself, to replace like with like and eliminate the variables. 

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