What is wrong? I was using my JD Z345R all morning hauling wood around with an attached trailer. Started and stopped many times. Then when I was putting it away in my shed and turned it off I hear this very loud and I mean loud buzzing. I had to disconnect the battery for it to stop. Then, with the key off position, I reattached battery cable and it started to turn over. It wouldn't start fully until I turned the key to the on position. Then it would run. Turn the key off and the loud buzzing started again. I recently replaced the solenoid with a new one last week. Any ideas?