^^^Another invaluable tool is a Ford EVTM for the particular year van or E-Series you're working on. I myself couldn't imagine tracking an electrical issue without one.
Looking around on eBay which is my normal go-to source for such things I don't see any 2000 E-Series EVTM's though. Time permitting I'll send inquires out to several sellers who might have one but not listed. Should I find something I'll post it here or contact you via PM.
Usually I don't advise using an EVTM from a different year but for the 2000's something from 1999 to 2001 would be close. If nothing else you'd have circuit paths but wire colors and pin locations slightly different so know that if you buy one from those years.
HTH