Fordson major diesel convert to negative earth

thanks,
from Pat, England.

To answer your questions directly:

1. You can use an alternator from a car, as long as it produces the same voltage as your battery (ie., 6V or 12V). I used an alternator from a Ford Fiesta, as it is fairly small and cheap from a scrap yard. Petrol/ diesel does not matter.

2. The starter motor will work correctly (the current in the field and armature windings will both reverse, giving the same direction of rotation).

3. I think at least you will need to cross the wires on the ammeter for it to read in the right direction. Note that a modern alternator is likely to produce a higher output current than the old generator, so you may need to replace the ammeter for one that can cope with the full output of the alternator (eg. Ford Fiesta alternator=55Amperes). One further thought, you may need to change the wire to the battery for a heavier guage to cope with the higher current.

4. I don't know where the regulator is on a Major. On my Dexta, I removed it, as the alternator I used has an internal regulator. The large terminal of the alternator goes to the battery positive (I put a 60Ampere fuse in this wire just in case!). The small terminal on the alternator will need a switched live connection from the battery positive (eg. through the ignition switch if you have one) via a bulb of the same voltage rating as the battery (This provides a charge/ no charge indicator).

One benefit of changing to an alternator is the greatly increased battery charge rate due to the higher output current. Plus you will still be charging when using lights, etc.

Mail me if you need an more details.

Hope this helps.
J-P

PS. Brian helped me a _lot_ with this stuff a year or so back. I also thought that my dynamo was broken. If you use the search function on this board, you'll find the posts.