2000 Thomas MVP 5.9cum At545 pusher shifter assembly.

[DDMasterTech3926]

Does anyone know what the black box is on this shifter assy? The at545 has a neutral safety sw at the back of trans so I know it's not that.
But it has wires and rev/neu scribed on it...

 

[DDMasterTech3926]

View attachment 869258View attachment 869259
Does anyone know what the black box is on this shifter assy? The at545 has a neutral safety sw at the back of trans so I know it's not that.
But it has wires and rev/neu scribed on it... View attachment 869260

Also :
The customer is having an ongoing issue, not being able to start the unit but you can wiggle the shifter back and forward and eventually cycle the key to start engine.
I have followed the entire length of the shift cable, checking for damage or slack, the cable is in adjustment and snug when shifting through 1,2,3,D,N,R