another electrical problem

the power went out to my pad the other day and when I went out today to run the gennie it wouldn't show any power in and wouldn't show a charge and showed a fault red lite on the inverter board.Sooo,I started with all the things I could think of as far as checking the gennie wires,fuses,circuit breakers,etc,but to no avail.
I figgered that while I was up there,I would clean and fill the batteries.Okay, and what is this loose wire that has corroded off the hot post for? I just cleaned and sprayed the terminals last month and everything looked ok then. I cut the end off the wire and was starting to put it into a new connector and noticed that there are yellow,white,red,black,blue or green and a brown wires going into the plug and the plug is toast.:(
Now is this the plug for the inverter or what and where can I find one? I don't think I want to go anywhere w/o it and we're heading out on wed.