Thanks, folks, for all the good clues on the red wire issue above! I have a 2009 LTX1046 and had the same symptoms with the PTO cutting off at medium speed, as well as the no-reverse cut-off. I added 6 inches of wire, soldered and taped, to both the green and red (mine was black and white, but I traced it upstream and found red) wires. To answer the question from HU-680248234 above, yessir, you were correct, that was the location of the red wire connection. Note that what you were referring to is actually a blade electrical connector. I pulled it off with needle-nosed pliers and replaced with a new one soldered onto the end of my red wire. After reinstalling, give it a squeeze with pliers to ensure the new one stays in place. Views below are from below and the top (through the battery hole).

OH NO! You can e-mail me for a PDF manual covering tests and adjustments to the PTO clutch, though it might be too late unless there is enough of the wiring left intact on the PTO clutch for you to repair and reuse (or at least...repair and test). Your symptoms sound like the PTO clutch might have a break in the wiring inside. This could be causing the the increased voltage that you note on the volt meter when the blades stopped spinning after you engaged the PTO. It would be normal for the voltage to drop in the PTO circuit when current was flowing all the way through the PTO coil wiring (because the wiring is carrying an electrical "load"), then when the supposed break in the wiring opened and no longer carried any current, the voltage would jump to a higher level on your volt meter (because the electrical load is gone now). The fact that the PTO stops spinning the blades but you still show voltage in the PTO circuit says your PTO switch is good and the PTO clutch is bad.

JD belt changes are designed to be done only by the dealer! Not surprisisng! I had a JD tractor that needed a main drive belt, and it took me almost a whole morning to figger out where i was going wrong, since i figgered they had sold me the wrong belt. Finally got it on! Jack the tractor up high, support it well, get a large piece of heavy cardboard, lay down under it, and inspect it very carefully, and i'm sure you will find how to replace the belt, without resorting to cutting out any brackets!

Well now, just because the PTO "stays engaged all the time" does not necessarily mean that the PTO clutch is actually "electrically energized". If the PTO clutch bearing seizes, or if the clutch plates have become stuck together, the clutch might be "engaged" mechanically. If............the clutch is really being engaged electrically in the manner you describe, you should be able to hear the clutch "snap" into engagement when you turn the key switch ON & OFF, or, by getting under the chassis and unplugging the clutch wire connector while the key is ON (engine not running off course). If you here the clutch engage as you plug and unplug the clutch wire connector or turn the key ON & Off (with PTO switch OFF) then someone might have tampered with the wiring at some time in the past. But if you DO NOT hear any click of engagement, then the clutch may be locked mechanically due to a defect as I mentioned above. To check for the clutch being locked mechanically, try to turn the clutch by hand with the engine OFF. If you are unable to turn the clutch in this fashion, the clutch might be locked mechanically. Top confirm if the clutch is locked mechanically, unplug the clutch wire connector and try starting the engine (but not while you are under there). If the blades are turning with the engine, the clutch is locked mechanically. Some clutches have a replaceable bearing while others do not. The presence of a snap ring next to the bearing indicates a replaceable bearing. If the bearing is "staked in place", non replaceable. This machine sounds as if it is not your personal machine ("This is a mower we use at my son's ball field."), so the possibility someone has surreptitiously monkeyed with wiring could be very valid. If you want to proceed with some testing, please create your own new thread on this issue. I think this thread has been hijacked enough. A new thread will keep everybody separated.