Voltage regulator connections to the D+ terminal (Bosch only)

Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police models

Updated: 2014 December 02

Charlie Mullendore of Antietam Classic Cycle brought to my attention a wiring connection dissimilarity amongst the Bosch voltage regulators.

Charlie noted that some Bosch voltage regulators secure the D+ terminal to the voltage regulator via a wide spade terminal; other Bosch voltage regulators use a 5 mm ring terminal. From a couple of photos Charlie sent, I did some digging and discovered the following:

• I believe the voltage regulators that use a wide spade terminal to secure the D+ terminal are the earliest voltage regulators. The example photo Charlie sent shows a Bosch part number of 0190350055. This voltage regulator is rated at 25 amp.
• I believe the voltage regulators that use a 5 mm machine screw to secure the D+ terminal are the later voltage regulators. The example photo Charlie sent shows a Bosch part number of 0190350068. This voltage regulator is rated at 30 amp.
• All of the modern replacement voltage regulators I've seen use a 5 mm machine screw to secure the D+ terminal (both the mechanical and electronic versions).

To the best of my knowledge, both the Magneti Marelli and Bosch generators are 25 amp units. It makes sense that a 25 amp voltage regulator would be fit to it. Unfortunately, I cannot find any picture of a Bosch voltage regulator in the spare parts catalogs by which to perform a visual confirmation.

Who knows why the observed difference? It could be a commonly sold aftermarket voltage regulator? It could be fitted from the factory? The original battery was rated at 32 amp/hours, so a 30 amp voltage regulator would have worked just fine with it.