I believe, if I'm not mistaken, that after 1996 that a second solenoid is not used for a Ford starting system, as the two-solenoid starting system was OBD-I, and not OBD-II. The starter relay that you are looking for would be located underhood, in the Power Distribution Center box (where the underhood fuses are). It should be listed on the box cover which relay is the starter relay.