Engine Won't Turn Off

[98BluBrd]

Hello I am new to the forum. I have a 1994 Yamaha V4 115 hp 2 stroke. About a week ago I pulled the boat out to make sure everything was working right before I took the boat out for the day. The engine and everything started up like normal but when I turned the key off the engine wouldn't turn off. I ended up replacing the key assembly (ignition switch) it strated right up and turned off fine. I ended up puting the boat away since It was to late to go out. I was going to be taking the boat out tommorow so I decided to check everything again today and it had the same problem again with the new switch. Is there maybe a short somewhere that is causing the switch to fry in a short amount of time? I have tried to follow the wires back to the motor and can't tell exactly where they end up. Is it possible that the new switch was just a poor quality? When I start the engine everything sounds normal it just wont turn off. Any idea's or help would be greatly appreciated.

I just want to get out and go fishing.

[98BluBrd]

It looks like I may have figured it out. I think the ground wire from the engine block has been damaged somewhere along the way. When I hook up a voltmeter to the power and ground (wires that are to the switch) I get little to nothing. When I hook it up to the power and a ground (that I know is grounded) I get 12.1-12.3 volts. I currently have a ground from the battery hooked up to the switch and it is working fine. The motor is turning off just like it should. I was wondering if it is ok to have the ground wire (to the switch) from the battery or should I run a new ground from the engine block?

[98BluBrd]

Anyone have some input?