Toyota Repair: 1985 toyota 4x4 pickup sr-5 Charging system help, toyota 4x4 pickup, fuse box

Question
So the other day when i was coming home from work, my truck had died while driving....the battery was dead. Over this past month or so my "charge" light came on. Didnt think much of it other than that i was a cable that runs from the fuse box under the hood, onto the the positive terminal battery cable. I;ve had this truck for about 3 months so the wire was like that to begin with. Its basically connected with electrical tape and nothing more. So when my battery died, i assumed it was causing a short to where my battery was constantly draining. I dont know know though. it could be something else...which is why i'm here. I need help fast...today is my day off and hope to replace that by the end of the night. Hopefully you can tell me what exactly that cable is for and if thats the root of the problem. If so, how do i go about replacing it....Thanks a lot! :)

Answer
I don't have any wiring diagrams for a truck that goes this far back but I think that cable is the main power cable to the electical system, they also used fusible wires between the battery positive and the fuse box, the wire is availble at most autoparts stores, use the same gauge wire and about 2 inches of fusible wire rated at at least 80 amps and connect to the battery and the fuse box connection.