Solenoid on governor

[sudsy1279]

My tractor quit running. I narrowed the problem down to the solenoid mounted on the governor. I purchased a new solenoid. It will not retract when the key is turned on. It will retract when wired direct, but becomes very hot if left retracted. I have 12 volts at the plug, and the two ground connectors show a good ground when tested with a test lamp. Is it possible that the starter key switch is bad? And what holds the solenoid pin in once the engine has started?
 

[sudsy1279]

I recently wrote about a problem I had with a solenoid. I forgot to mention that it was a Cub Cadet 7275 Diesel Tractor.
 

[t.r.k.]

I am thinking one of those 'grounds' is the hold in winding and should get power when the key is on. The other one is the pull in winding. It only gets battery voltage when cranking to retract the solenoid and allow the unit to start.

(No experience on Cadets, but that is how it is on older Grasshopper mowers with Kubota diesel engines in them.)
Sounds like the problem is either a bad connection in the wiring or in whatever controls the hold-in circuit. (Grasshopper uses a module. I don't know how Cadets are powered.)