I have a old model JD 160. The solenoid recently went out on it and I went to the local JD dealer and purchased a new one for about $75. I got it home and installed it, but now as soon as I hook up the battery, the starter starts to spin without the key. I check the obvious and wires are hooked up correctly and nothing shorting that I can see. Could this just be I got a bad solenoid?