Engine Why does my JD 332 engine cut off? plus more........

Hi to all...well, seems that my trusty JD332 is no longer trusty as far as operating goes; it has been the best tractor I have ever owned, love the instant start and fuel sipping status BUT - recently I have been experiencing problems with it. When I initially start it, and begin mowing, all is great, no issues what-so-ever. After no specific time of operation, from 15 min. to an hour (shorter time more frequently now) the engine quits. Since there is no power to the fuel shutoff valve, I have wired it to the open position (pushed in full) and presto - runs like a champ again. I have removed the wire in some instances and found that the solenoid works fine sometimes, but eventually quits again. I realize that that temp fix is not desirable, hence need a correct fix for it. Oh yeah, there's more.......
Also happening (most of the time) when the fuel shut-off valve voltage quits, so does the mower clutch/PTO up front. I have also hot-wired that with battery source (switch off even) and it powers right up again. The dash monitor light also lights up (again, with PTO switch OFF). I very much dislike this situation but am forced to do it or my lawn goes in-mowed until I purchase another mower (~5 Acres mowed). The PTO also sometimes engages when the solenoid is operational (voltage provided to it randomly). I am frustrated, do not know where to check first to see where voltage fails to be passed to the PTO and fuel shut-off solenoid. I suspect that one of the safety switches is at fault when it/they get hot (the seat switch is bypassed, done by previous owner and I never corrected it).
So...now you know my problem, and I am hoping that one of you sharp JD guys can come up with a solution, or at least a trouble shooting procedure. The only switch(es) I know the location of is under the seat, and under dash at top where forward-reverse drive arm sticks up through the dash plate. Any advice? I am open to all offers, hopefully someone with chime in. Thanks for your considerations and help! Bob

I would strongly suggest you buy the JD technical manual for your mower.
It is a Yanmar rebadged green & yellow in a contra deal when JD made some bigger tractors badged Yanmar.

Not something I would consider trying to diagnose over the web as it is a complicated mower.

Some generic things like cleaning all of the wires, particularly the ground strap at both ends and the main power wire both ends and from memory there is another ground strap between the chassis & the engine.
Unplug both power boards spray the plugs with WD 40 or contact cleaner then plug & unplug then a dozen or so times to clean the contacts then spray again & blow off.
Do the same with the fuses on the boards

The JD manual has step by step instructions how to diagnose the problems then how to fix them.

The only "random" problems I come across with them is conductive dust shorting out the control boards ( blow clean, spray with electrical cleaner like WD40 then blow again )
And debris blocking off the lift pump inlet or actually clogging the pump & burning it out.

The manual is 600 pages written so some one who has never held a screwdriver can totally rebuild the engine

Both the 300's I service are the diesel engined ones

Hi Bertsmobile1 - appreciate your good advice on JD 332 Manual purchase and on hunt for one now. Will also take your advice and check ground straps and unplug all plugs, clean and lubricate with good electrical cleaner etc. These are things I can handle for sure - I might venture down to the JD dealer and see if I can chat with one of the mechanics. They might suggest I replace such and such, which I will consider and see if their repair suggestion works.

Again, thanks for the great input - have a great weekend while "down under"!

Bob