Ed, the alternator has probably died (or at least the voltage regulator has).
 Check the battery voltage with van off.  Now start the van and rev the
engine a little.  Now check the battery voltage again, if it is lower than 13
volts then the alternator is not putting out.  Check to see if the alternator
belt is tight (and there).  If it is then check the Voltage Regulator.  You
can take the voltage regulator out pretty easily by undoing two small screws.
 See if the brushes are OK.  Check the play in the alternator pulley by
loosening the belt and trying to cock the pulley from side to side with your
finger and thumb at 9 oclock and 3 oclock respectively.  Then try it again at
12 oclock and 6 oclock.  If the alternator has some play in the bearings then
it would be a good time just to replace the whole thing with a rebuilt unit.
If not then you could give a new voltage regulator a shot.  I have new
voltage regs (Bosch) for $45 and rebuilt alternators (which have new regs in
them) for $150 plus a $75 refundable core (Bosch).  Let me know if I can help
you.

Thanks,
Ken Wilford
http://www.vanagain.com
John 3:16

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