As the title says my 318 cuts off like the key was turned when I flip the PTO switch. The previous owner deleted the seat switch (I do plan on re connecting when this issue is solved), so I don't think that's the issue. It starts and moves just fine. The issue came up when I was out mulching leaves. It seemed to work great until I turned the PTO off then tried to turn it back on to no avail. I took the seat pan off and looked for splices and only found one (see pic below).that green wire runs to a aftermarket switch installed in the dash. The switch also has a wire running to the battery with a 20A fuse in the line. The previous owner said it was installed as a "cutoff switch". It has to be turned on for the tractor to start. I attempted to remove it, but the tractor won't start without it. I'd like to get rid of it either way, but don't know if it's the source of my issue due to the fact that the PTO was running fine before with the switch installed. Other issues that might help- the battery light stays on, and sometimes the tractor won't shut off with the ignition I have to use the previously mentioned switch to shut it down. I'm absolutely stumped. Sorry for the long post and thanks for your help/time.