PTO won't disengage

[Toyman]

Looking at an M5030DT and found a few issues. First, the PTO will slow when the lever is pulled up (but not stop), and conversely speed up when the lever is engaged in the down position. Engaging the clutch stops it. Not sure if this may just be a linkage adjustment or a deeper issue in the PTO? I visually saw the linkage working/moving and the lever felt positive in both positions. This was done without having a piece of equipment attached. It also seems to have an electrical gremlin. Lights, dashlights, and water temp gauge all are not functional, along with the battery draining if it is not disconnected. I've looked a the wiring diagram and it doesn't look too involved but looking for some thoughts. It fires right up, no smoke, runs strong and holds gears well, but the two items mentioned have me concerned.

 

[GeoHorn]

Clearly you are observing an electrical/wiring problem which must be delved into and resolved. Mice eat wiring and are more active during the winter months as they evade the outdoors and look for shelter in equipment.

 

[PoTreeBoy]

Based on just the parts diagram - I didn't find a WSM - I think your PTO keeps turning just due to fluid friction. The parts list doesn't show a PTO brake like some tractors have so it's relying on bearing friction to stop.
If you can do this safely, with the PTO in neutral, apply some resistance (shouldn't take much) with a short piece of 2x4 or equal. If the seller has a mower you could ask to check the PTO with the mower attached.