We have a 1968 3020 diesel. replaced both batteries and cables. The problem is when I hooked the small ground wire up it sparked bad and the starter motor run continuously. When we got the tractor that wire was not on it and the cables were crappy which is why we replaced them.
If I took the ground wire off everything worked fine. Polarized it before starting the tractor. Run it about 1 1/2 hours and now all it will do is click. Batteries are dead.
Any suggestions or ideas?