I'd look closely at the diodes in that charger, they tend to be a frequent cause of breaker problems in most chargers.Sometimes you can visually see that they are burnt although they can be bad without any visible signs. You can use a continuity tester on them to verify that voltage flows in one direction only cause continuity both ways will trip the breaker or blow the fuse. Also check and be sure you don't have a short to ground somewhere on the cart, headlights and accesories are the usual cause of those problems so if ya have any disconnect them and try the charger. Hope this gives ya a couple ideas anyway. Good luck, those type things can be a beast sometimes