I have an older gas ford 3000 tractor. It was moved out to a field about 2 months ago and parked. You can turn the key on it and the dash lights up and then when you turn to start it, it just quickly buzzes/clicks and then stops. Then the dashboard lights go off and it won’t click again if you turn it again. You have to disconnect and reconnect the battery terminals and then it will light up and click, but it never turns over or sounds like it’s trying hard to start. It does have a new battery, and when it’s not being used we remove the connections to the battery so it doesn’t drain. What could this be?