The negative cable, which is normally connected to the negative pole of the battery, is fastened to the crankcase. From here, the cable branches off and splits up within the electrical system to carry the ground connection to the different elements in the system.

The image shows the ground connection on left side of the engine crankcase.
The battery charging circuit and power distribution
Electrical power for lighting and signalling devicesRemoval of the starter motor idler gear
Slide the gear pin (21) complete with the gear (19) and washer (20).
Warning
Pay attention to the washer (20) since it may fall inside the
crankcase half.
At this point, it is possible to remove the starter motor as described in
sect. 6 - 3, Starter motor. ...
Charging the battery
Before charging the battery, it is recommended to remove it
from the motorcycle.
Important
The battery is housed in the cowling, always contact
a ducati dealer or an authorised service centre for its
removal.
Remove the left cowling (1, fig. 137) Loosening:
side screw (2, fig. 137) Retaining ...
Using a multimeter to check the electrical systems
Introduction
This instrument allows you to measure resistance, voltages, and current
values. Multimeters can be divided into two basic
types: analogue and digital display multimeter. An analogue multimeter has a
pointer display. The dial is marked with the
scales to be used for measurement of ...