IHI Mini won't shut off with key

[Bad Night]

I have an IHI Mini excavator with a 4 cyl. Izuzu motor . About a month ago it quit shutting off with the key . I don't use it everyday so I hasn't been a big issue . I can extend the bucket way out and stall it out . So today I was going to look into fixing it , expecting to see a broken wire or something . I can't really find anything and don't know where to look . It actually dawned on me that I don't know what turns a diesel off . Does turning the ignition sw. off kill power to the injectors or injector pump or what ? Anyone have any idea .

 

[JLDickmon]

if electronic injectors, it would shut the injectors off..

everything else it kills a solenoid that controls fuel flow to the injection pump

 

[Bad Night]

Ok thanks . I'll be working on it again tomorrow evening .