wire charging circuit
 

I have a Bosch Alternator that has a fault in the charging circuit
I intend to wire a relay to give the Field a voltage reference when the car is running
Do I need a bulb in the circuit to drop the Battery/Reference voltage, keeping an offset between the Field, and Battery ..???

Model, year would be good to add to you post and your signature

Welcome to the forum

typical 2 wire bosch alternators with internal regulator require a 3W bulb on the D port with a live on the other side of the bulb, otherwise the alternator wont start or umm excite.

1990 Merc SE300
the Alternator charging circuit is nearly the same for all Bosch

3w .. could be a
"1024" then ..

thanks ...!!