Thanks Jon for the advise. I will replace new splice, and the burned one may be a butt connector, not sure yet. New wiring around the splice is a good idea, and I will use bit longer new wire section to make crimping job easier.
I was wondering if I replace the wiring section that is not so difficult to replace with 8 gauge insulated wire and 8 gauge connectors or splicer, would it help or will it be worth the trouble using crimpable step up connectors.
I have used 10 gauge trailer brake wires that is pretty well protected but not sure if there is a good heat resistant insulated 10 gauge out there.