Both high and low are normally supplied by that same #12 white/black wire.

The #16 red wire is for a different purpose, the "flash". It is red to
warn you it is always hot. It lights both bulbs while the hi/lo stalk is
held up, whether the light switch is on or not and whether the key is on
or off. This is a feature that many people have used to get home in the
dark even when the headlight switch has burned out or the contact for
the headlights in the key switch has fried.

Mark

neil n wrote:
>.........
>
> Of note, find it interesting that on the '81 gas, #12 wire supplies
> the low beam, but hi beam is supplied via #16. Don't hi's take more
> juice? Or is this done b/c #16 supplies the hi beam "flash"?
>
> Neil.
>
>