I have a 2305 with 170 hours on it. After running the tractor for about 30 minutes. I attempted to turn it back on about 15 minutes later and I only got a buzzing noise from under the steering wheel, with no engine turn over. It ended up being the glow plug relay. Also, when "shifting" the range selector to/from high low (key at on pos.), another relay also buzzes. Voltage at the battery is 10V. Didn't get a chance to try another battery. Could this just be a bad battery? Any thoughts?