Hello and thank you very much for answering.
There are two contactors, both work fine when removed.

One (50438766) for the hydraulic pump, it is not switched on: A1 = 24 volts, A2 = 6 volts (only wire disconnected, otherwise 24 volts).

The other (51296863) for the electric motor, it is not switched on: A1 = 24 volts, A2 = 5 volts (only wire disconnected, otherwise 24 volts).

24 volts is present on the contactors just after turning the key.
The two contactors can be engaged when I connect A2 to 0 volts (with A2 wire disconnected).

the hydraulic pump is working.
the electric motor has resistances of 0.4/0.4/0.5
nothing happens when forcing the contactor of the electric motor.
Only the horn works

What can I check?
Thanks in advance