​RE: Headlight Switch
Between Ken and Mark and info on the Van Cafe website my question seems to
have been answered.  My VIN has year letter 'L' for 1990 and the build date
is late 1990 on the door jam.  And IIRC the switch that went south had
suffix M and the used replacement switch had suffix B but M replaced B at
some point.  Therefore I don't need the later T suffix switch that is
primarily found in the '91 Vanagons.
Mark's info on the addition of a fuse to part of the light circuit '85 on
is even more interesting.  Another reason that supports my belief that
later model Vanagons have a lot of electrical (and mechanical) improvements
that are desirable.​