I don't have that option on my vehicle, but no doubt it is looking for a certain current flow to the headlights. Without really knowing, I'm going to guess that the feature is incorporated into an electronic module. The Windstar wiring diagrams would go a long way to determine exactly where and how.
It might be fixed with a simple adjustment in the module. On the other hand it might only be "fixable" with a significant hack to the circuit.
You might want to read this post from the AF Engineering forum:
http://www.automotiveforums.com/vbul....php?t=1138754