Recently it's become worse. It turns out the big cable from the main
power disconnect to one of the big contactors (PTO?) is getting stinking
hot. I've removed the access panel below the dash now, and when things
start slowing down that cable is too hot to touch for more than a
second. It's at the point where I have to park it and let it cool twice
to get everything mowed (3/4 acre). The insulation is hard and cracked
at that end, and the wire is corroded. The ammeter wire on the same
terminal is also pretty well cooked.