Cool...
Something I found...
Q: I was told that my 1999 Windstar has "Low side switching." What do I need to be able to enable the lighting circuit on my trailer?
A: Indeed, Ford has changed the wiring configuration on the '99 and newer Windstar models and also the 2000 Lincoln LS series vehicle. You will require a "low side switching adapter" which can be installed by your dealer are any competent trailer hitch installation facility. Beware however, this wiring procedure is not for the "faint of heart" wiring mechanic. One mistake could cost you serious dollars, so leave this one to the professionals! Low side switching is similar to having a positive ground effect. When the signal light is on, the power going to it is off. The signal is modulated, so you cannot take power directly off your lighting circuit. The adapter uses the lighting circuit to switch power on and off remotely from the vehicles battery. This in turn applies power from the vehicle battery to the trailer instead of the lighting circuit.
Wonder if the kit takes care of all of this, this is exactaly what the hitch place said that I called too..