Hi everyone! New to the board! I have two JD 420's. One, I've had for several years and had been working just fine until about two months ago. Now when I turn the key all i get is a click. i've changed out battery and still just a click. I have another 420 that has a similar problem. Replaced starter, ignitiion switch, and battery and still just gets a click when I turn the key. I installed an ignition switch from my 300 and it fires right up. It seems I got the wrong switch. What problems could I encounter if I put an ignition switch from the 300 onto my 420?