I have a 97 EZ Go Medalist. I have older Trojan batteries in it but they were running fine. I had it for sale in the yard and found it with the key on and the batteries dead. It was so dead that it wouldn't charge. I charged it with a trickle charger and the digital meter has risen but it flashes back and forth and the cart will not go or charge . I have cleaned all contacts and even replaced a cable that I knew had some corrosion on it. It still will not go. Any ideas?