If they are still stuck at this time, and don't have a relay kit on hand to
install in the field, they can bypass the starting circuitry and use jumper
cables straight from the battery to the starter solenoid.  This may get them
home, then they can work on a permanent solution.  Clamp onto the smaller
wire on the solenoid, run cables around right side.  Sit in driver's seat,
turn key on, lean over and attach cable to battery to turn engine.  When it
starts, pull it off, retrieve cable, drive away.

Of course, I assume any vanagon owner has jumper cables onboard at all times
;)

Bill Marshall