Ive had an inquiry about converting from a lucas dynamo to a delco 10 si alternator. It is better to connect this new wire directly to the battery cable and leave the original brown wire to supply the normal amount of power to the rest of the electrical system.

Vincent Motorcycle Electrics
Dynamo to alternator conversion wiring diagram. Disconnect the battery and remove the black regulator box from the car taking care to make a note of or label each wire removed with its original terminal connection. A relatively modern alternator only needs two wires to do its job. Dynamo to alternator conversion. Often the insulation on the factory wiring is cracked and frayed inviting short circuits and other electrical problems down the road for wire terminations at components use crimp on ring type wire terminals. The relevant belt gcb10825 is also needed. I dont know if that is original or if it has been changed later.
Some people recommend that you fit a thicker wire from the alternator output to cope with the potentially higher current. While the conversion reduces the authenticity of the antique mf 35 if you use the tractor for agricultural rather than collecting purposes the conversion increases its value and the dependability. I believe older models came with positive ground whereas my own 59 has negative ground. It needs a small wire that goes to the light on the dash and it needs a heavier wire that carries the current out of the alternator and to the rest of the car. Lets talk about wiring. This fellow has an fe35 which is earlier than 1959 and it presently uses positive ground.
One of the easiest and best improvements that can be made to an older tractor is to replace the original generator with an alternator. 12g1053 as the alternator is shorter than the dynamo. Alternators do a much better job at charging a battery at the low speed tractor engines are usually operated at. Replacing the generator with a gm one wire alternator is recommended. Highly recommend running new wiring for the alternator rather than adapting the existing generator wiring. We can deal with two wires.
As an alternative to this double wire scheme you could run one larger wire at least 10 awg from the alternator to the battery cable. The wire in. Fit the alternator using the necessary rear support bracket part no. The two thick wires should be joined unfused battery charging and the others go to various circuits see wiring diagram in workshop manual and could be fused as required. Two wires isnt intimidating at all. Converting a massey ferguson 35 from a generator system to an alternator power converter improves the implements electrical performance.