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 rear-view mirrors
Start the screws (2) in their thread on the rear-view mirrors (1), inserting
the washers (4) as shown in the picture.
Insert the rear-view mirrors (1) in the u-bolts (3).
Tighten the screws (2) to a torque of 25 nm +/-10% (sect. 3 - 3, Frame torque
settings).
Warning
The left rear-view ...
Instrument panel on handlebar
Lcd.
Neutral light n (green). Illuminates when the gearbox is in neutral.
High beam light (blue).
It turns on to indicate that the high beam lights are on.
Engine oil pressure light
(red).
Illuminates when engine oil pressure is too low. It must turn
on at key-on, but ...
High engine coolant temperature
The activation of this (amber yellow) "warning" indicates
that the engine coolant temperature is high.
It is activated when the temperature reaches 121C (250f).
Note
In this case, ducati recommends stopping and shutting
off the engine immediately; make sure that the fans are
workin ...