I have a Grasshopper 725 D & having trouble with PTO switch that I changed 2 times & is bad again so I wired it to a toggle switch. It does away with some safety switches but I am the only one that uses it. After I did that I tried the PTO a couple times then shut engine off. A while later I smell smoke an saw it was coming from the fuel stop solenoid. It got very hot and burned up. I don't think the solenoid is suppose to have constant voltage to it. What did I do wrong?