Most of the late model Fords use a Generic Electronic Module (GEM) to control the door locks, windows, dash warning lights, front wipers, and a host of other features. There are usually 4 fuses identified as GEM for these functions. Your Windstar does not appear to use the GEM, there seem to be separate functional modules for locks, and there is a front electronic control module and a rear electronic control module. So your vehicle is different to what I am accustomed to.
In looking at the fuse box in the passenger compartment, you have 6 relays. The relay #1 and #4 are named switched system power relay #4 and #3 respectively. I am unsure of your setup, but typically there is one for accessory and one for run. When the ignition switch is turned to start the power is cut to most ignition fed systems (to ease the starter load) and returned to power when the ignition returns to run. Sounds like the relay does not return to the run condition but this is purely speculation on my part.
I have no way of checking the electrical circuits for your van, but you could see if both relays are the same setup of contacts and interchange them if appropriate. They are not usually expensive anyway.
I will check my Taurus and let you know.
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Art
2000 Taurus SEL Wagon 3.0 Vulcan (daily driver)
1993 Taurus GL Wagon 3.8 Essex
1991 Mercury Grand Marquis LS 5.0
1986 Chevrolet 3/4 ton pickup 4x4 350 with turbo400 and 208 transfer case
1978 Chevrolet 3/4 ton pickup 4x4 custom 6.2 na diesel with turbo400 and 203 transfer case
Planning 2008 Taurus X in a year
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