I have early 2000 model John Deere Sabre and i cannot get it to crank, it will start up just fine if i jump it and run for however long i need it. However as soon as i turn it off within 5 minutes i cannot start it, i have to jump it again. Witohout the jump the starter will pop up on the 1st crank and die down to nothing like it is getting no power within seconds. (the Battery is brand new). Any thoughts?