bcm vs ignition harness

What is a "military splice?" Let me go try googling that and see what I come up with.

To save us repeating ourselves, look in the section here on General Discussion. On the first page are two very long and informative threads on soldering and connecting. This thread is rapidly turning into 101 on auto-electrics, I've neither the time nor inclination for such basics and reading those threads will help you to understand. Just about every query ref: car electrics has come up before, just look in the archives.