I have had this problem on customer's vans before and I have found that it is
the number 13 relay in the rear of the van (driver's side housing).  You can
stop by the shop and I can swap in a new one for you, just to be sure.  Let
me know.  I have these relays in stock.

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

New Phone (856)-327-4936
Shop: (856)-765-1583
Fax:     (856)-327-2242