The S1 Fulvia's have dynamo's except for the Fanalone. The S2 and S3 Fulvia's have alternators made by Bosch or by Ducellier. The early ones tend to have Bosch, the later ones Ducellier. The connections and wires for both types are different. On the coupé's the voltage regulator is mounted on the right hand side behind the head lights.

Bosch supplies electronic voltage regulators to replace the old electromechanical ones. The Bosch 0 192 062 007-850 is a direct replacement for the original voltage regulator and is mounted in the same place. The Bosch 1197311090-850 can be built into the alternator itself and comes equipped completely with carbon brushes. Remove the old plastic part with the 3 pin connector and the carbon brushes from the alternator and mount the new electronic voltage regulator. The original 3 wires going to the original voltage regulator are no longer used, which means that the alternator / engine / gearbox combinations is no longer electrically connected to the body. This connection is normally done through the gound wire of the 3 wires going to the voltage regulator.

Important notice: if you do this replacement, you have to connect the engine electrically to the body with at least a 2,5mm² wire, preferably 4mm²!!!!! If you don't do this, you will have all sorts of spooky electrical problems as the minus voltage will probably run through the choke cable, which is a very bad electrical connection. Note that the cross member holding the front spring is NOT connected to the body. It is connected to the engine / gearbox with a thin wire dimensioned to carry only the return current of the horns.

For the Ducellier one you have to find a universal electronic replacement that can be mounted on the same spot as the original one. There are quite a few around. Very cheap usually. I have not found one yet, which is mechanically identical to the original one. So you may have to improvise a bit with mounting and perhaps change the connectors on the 3 wires through which the voltage regulators is connected to the alternator. Make sure you connect the right wires to the terminals. The black wires is also connected to the body. Make sure there still is a connection to the body after installing the new voltage regulator.

On alternators there is no need to have the current limiting done by the voltage regulator. The maximum current is sort of built into the alternator itself. Your car electrics shop will usually be able to find a replacement for the Ducellier one.

Huib