Took a couple hours on the new tractor yesterday. As a reminder the PO suggested that the PTO clutch was blowing the fuse, he said he measured it at 0 ohms.
The hood was adjusted too far forward anyway so I pulled it off finding only 2 of the 4 bolts that should be there. The PTO clutch showed 3.5 ohms which is exactly in the middle of the 3-4 ohm range. I took a 12v drill battery and applied power and could hear the clutch engage. The little jumper wires I had didn't get hot or show any sign of a short. There was a little pigtail on the wire coming from the switch, I disconnected that and hooked the wire to the clutch, flip the switch and the clutch engaged as it should.
Fire up the tractor and the clutch engaged but no hydraulics. Turns out theres ANOTHER clutch on the poorly mounted hydraulic pump. It looks like what happened was the pigtail used to go to that clutch also, got torn off and grounded to the frame which caused the fuse to pop.
I ended up reworking the pigtail, it was assembled upside down. I'm not happy with the routing but I just wanted to see if I could get the hydraulics to function.
Success! Lift goes up and down, bucket rolls. Everything I suspected about the hydraulic cylinders being too long is true, the lift arms are so long the bucket won't rest flat on the ground. 2" shorter cylinders would fix the problem.
I took a ride to Tractor Supply to buy some bolts since my local hardware store was closed. While there I looked at the hydraulic assortment and realized that everything on the tractor is from Tractor Supply. So the builder just bought stuff that was "close". So I'll be measuring and buying stuff thats right instead. Fortunately the rams all work so I should be able to sell them off to mitigate the cost.
Used the loader to haul firewood, I'm not sure its any faster than just using my garden cart but I wanted it to warm up and see if there were any engine troubles, there aren't other than the choke occasionally sets itself, the tower where the steering wheel is needs to come apart anyway, the bolster for the steering shaft is boogered, shouldn't be hard to fix.
Anyway the positive news for the day is I took a $1200 not-working loader and turned it into an $1800 mostly-working loader. Not bad for $1.00 worth of connectors.