My 21 year old Xj came with this option "BAFP 130 Amp Alternator" Along with the factory supplied wiring harness. And it has not yet burst into flames, during those 21 years. And So I'm willing to bet, It can go another 21 years without doing so!

 

I've had the most fire-related trouble with older vehicles. The combo of heat, vibration, age and heat (did I mention heat?) tends to do a number on harness insulation over time. The harness I pulled of of my '79 was so brittle it cracked when I disturbed it. (and the fuel lines weren't any better). Spark and fuel makes for an interesting combo when it's not contained inside the engine, lol.
Anyhow, it's a good idea to check things over every so often once they have a few years under their belt. Probably should consider primary wiring a regular inspection item.

 

And people wonder why I do annual inspections on my vehicles...

 

I used to have a Buick grand national...talk about a fun car..and the wiring was brittle on the injector harness and cause a fire!!...luckily I had a extinguisher and pit it out immediately. But that was very scary...due to old wiring