CHASING CiTROëNS

I’m trying to decide to do this or not. By the way, if you have a later D model, The Prestolite Alternator that fits late Studebaker Larks is an exact match for your D’s Ducillier unit. The Studebaker guys also have a Honda Alternator (Denso) that seems to work well — here’s the article for that:
https://www.studebaker-info.org/Tech/Alternator/Honda/hondaalt.html

A successful conversion from generator to alternator on so-equipped D models has been the use of the Delco 63A self regulated alternator, with pig-tail #148 for the field wire and dash light. The belt you need is 15-7390. To mount, use Mr Gasket Alternator Adjustment Bracket #9851, with the following modifications:

• Cut the bracket to 9 3/4″ (23cm) length, measured from the slotted end.
• Drill a new hole for mounting. Use 11/32 (9mm) bit.
• You’ll need some washers between the bracket and alternator. If there are quite a few, you can go to McMaster-Carr and get a properly sized spacer for super-neatness.
• Attach teh EXC wire from the Regulator wiring harness to the heavy wire of the pig-tail, and the “L” wire from the regulator wiring harness.
• Clean up the unused wires, remove the regulator as/if you’d like.