Wiring fire, advice sought!

Your typical 10 ga. wire is rated well over 35 amps. 10 ga. can be rated anywhere from 50 to 60 amps. The TXL wire that we use 14 ga. wire is rated at 35 amps. If the charging system was rated at 55 amps. which most were back then they wouldn't have used just one 10 ga. wire off of the alternator.