This is great info! Thanks. I will try these things this evening. I've disconnected the positive terminal on the battery for 10 mins to reset everything and ensured the battery was fully charged but nothing changed. I've swapped some relays but no change so swapped them back. I have some new ones coming in today too. Any idea how to determine where K05 Relay is located on the tractor? Again, I know where several relays are but don't know how to identify which one is K05.I would try the easy thing first and reseat all of your relays in your fuse compartment. If that doesn't fix it, Fuse F10 supplies the power to the safety circuit. S06 is the gear shifter neutral switch which is in series in with S02, which is your PTO switch, which is then driving the coil of Relay K05 of the safety circuit.