FINALLY found the thermostat housing and got the cold sensor switch replaced. replaced fuse and its starting like a champ. Now to original problem.
Cutting a field of 3-4 acres, starts up and runs for 30 - 45 mins then I can fill the power drop as I cut uphill. Another round and the Rpms drop to 5-10, then back up to 20, back down again then it cuts off. It will restart and run enough to get it back to the house (100 yards) but it sounds like its running rougher than when it first cranked up. If it sits overnight, it cranks up and sounds fine, then this cycle starts all over again. I'm thinking its running hot, but the engine compartment doesn't seem to be hotter than normal, and I don't now if the temp gauge is working. Maybe its not getting enough air or fuel.
I drained the water off the tank and filter, changed the fuel filter, added diesel clean, changed both air filters, oil and filter, new thermostat (that was fun), flushed radiator, new antifreeze, and the cold sensor switch. None of this helped. Took it out to cut grass, 30 mins later it cut off again. I can't figure what is making it cutoff, then starting back after it sits awhile that would not be related to it running hot. I couldn't find a radiator cap, but got one on order.
Any help would be greatly appreciated.