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 devicesRefitting the cylinder head assemblies
Warning
To prevent oil leaks past the contact area between cylinders and
crankcase, each time the head is removed, cylinder and
piston must be removed as well to clean the mating faces of crankcase and
cylinder and restore the spoiled gaskets and
o-rings and apply again liquid sealant (sect. ...
Maintenance indicator
This function indicates that the vehicle is about to or has
travelled a distance for which an authorised ducati service
centre should be contacted to have the general maintenance
or oil change performed.
Maintenance table
First warning - oil service 1000 km
The first warning is activated a ...
Removal of the clutch master cylinder assembly
Warning
The clutch master cylinder manufacturer advises against servicing of
the clutch master cylinder (1) due to the safetycritical
nature of this component. Incorrect overhaul of this component could endanger
rider safety.
Maintenance operations of the master cylinder are limited to replac ...