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 devicesWater radiators
Clip nut
Spacer
Vibration damper mount
Screw
Screw
Spacer
Vibration damper mount
Clip nut
Bush
Spacer
Rear sprocket
Screw
Water radiator (right)
Screw
Screw
Air deflector (right)
Special screw
Electro-fan
Screw
Vibration damper mount
Screw
Plug
Half ...
Refitting the airbox and throttle body
Position the filter box (1).
Operate on the vehicle lh side, connect connector (f) of the tps/div motor.
Operating on the right side of the vehicle, connect connector (e) from the
aps sensor.
Check for the vibration dampers (20) on the map sensor supporting bracket
(19).
Insert t ...
Removal of the intake manifold and coolant union
Loosen the clips (f) and remove the hoses (t).
Remove the manifolds (25) undoing the screws (21).
Loosen the clamp (a) and remove the hose (b). Remove the union (12) and
recover the seal (24).
...