Melex 512 won't run

[dwbarg]

Hello, My melex quit running. A couple of weeks ago my son and I were riding and we stopped and it took a second before it would move. I could smell some wires getting hot. We stopped again and it was done...no go. the wire on the middle left of the f/r switch was melted pretty good. Also the post on the same wire of the f/r switch was burnt along with one of the micro switches. I replaced the whole assembly and it still wont run. The solenoid is clicking. What do I check now? By the way, I checked the voltage on all batteries and they each checked 6.3v. Thanks for the help.