Re: JD 318 PTO will not engage - bad connections
My Craftsman had same issue. No PTO, or would work intermittently. Mine was simple. I'd pull the PTO switch up while pressing forward on it. That would work. Just operating it normally got nothing. After a while, no amount of wiggling or anything would make it work. Bought a replacement switch that solved the problem, and has worked for years without issue.
Maybe suggested already, but check for power to the switch when all else is in "go mode". If power in but none out with the switch in PTO position, it's the switch.
As AVE says, its where the gorilla meets the pixies, a most vulnerable device.
X 500 48" Deck 48" blade
Stihl BR 600
Sears Suburban Super 12 1968
Craftsman 1990 something LG Tractor 46" deck
Original Kohler 8hp Giant Vac early 1960s