About that front heater blower motor:
It's pretty much a given to remove the dash to get at it, but
thankfully that's not that hard.  I had to do this a few months ago
after my failing, noisey fan motor finally died for good, sort of (more
on that later).

I discovered though, at least on my '84, that the rear heater motor is
the same as the front heater motor, so if your rear heater is bypassed
you may be carrying a spare front heater motor and not know it.

It's pretty much a direct swap, and the only thing to do is reassemble
the dash, kinda fiddley.

I found that my "new" motor was intermittent, however.  The problem was
a crisped ground wire at the cluster behind the fuse panel, so be sure
to check the conditions of your grounds!  Admittedly mine probably
overheated from the increasing load of the failing motor, but it's a
good thing to check on.

Ciao,
Gregory Smith
Olympia, WA USA
'84 Vanagon