JD LT145 back to messign with it

So I can make it run or get the PTO to kick in but when the PTO does kick in it kills the engine. Seat safety switch does not work like it should. If the switch is in the seat and your sitting on it it will not spin over. Pull the switch and leave it so it is not pushed down it starts up. Push it down and the PTO will not try to engage but if you leave it up the PTO will engage but kills the engine. PTO has 3 wires going to it. I had hoped it would have 2 wires because that would be a simple one to wire around. So any body know what the 3 wires go to?? I am thinking one wire is ground. One wire it the hot wire and the 3rd is a safety switch wire. I have found I can get a wiring diagram for it but have to find the serial number for it before I can get that. Just for the heck of it when I was talking to the service dept of the JD dealer I asked about the 3 wires and they told me they could not tell me because it would be doing away with a safety device. Did not surprise me but figured it would not hurt to ask. LOL Talk a bit more to the woman and said well shoot my 1935 JD B has not safety devises and she said well back then people had common sense