That's a choke. They help smooth/suppress noise from the motor.
It's worth checking it's not failed and gone open circuit (either with a multi-meter, or apply the 12V with the choke in circuit).

Have you checked both fuses on the drive?
It could be the Inhibit needs a certain voltage applied, but without a manual, or being able to work out what the wire gets connected to and fed, it's pretty much guess work.