You may have a bit of a problem.
1999 Ranger will have PATS, passive anti-theft system, which shouldn't have starter interrupt, 1998 Explorer may have, not sure.
But in any case you will have a Starter Relay in the engine fuse box.
When you turn the key to START 12volts, from Fuse #24 in cab fuse box, will go thru the Clutch switch(manual trans) or Neutral switch(automatic) then to the Starter Relay in engine fuse box
Starter Relay,..... this relay is either Grounded locally OR the PATS module Grounds it, anti-theft part.
Starting backwards on the wiring.
Smaller yellow/light blue stripe wire on the starter motor goes to Starter relay in engine fuse box, <<< this is the wire that needs 12volts when key is turned to START
Starter relay has a Yellow wire connected to 50amp fuse in engine fuse box, this fuse has 12volts 24/7, all the time, it powers the yellow/light blue wire when relay closes.
The starter relay then has tan/red stripe wire that comes from the clutch or neutral switch, it will have 12volts when key is turned to START if..........clutch pedal is down all the way or Automatic is in Park or Neutral.
And a Black wire, this is the Ground for the relay.
So tan and black wires cause relay to close when key is turned to START
When relay closes 12volts on the Yellow wire is connected to the yellow/light blue wire which activates the starter motor.
A white/pink stripe wire runs from fuse 24 in cab fuse box to the clutch or Neutral switch.
Fuse 24 gets 12volts from key switch when turned to start on a Red/light blue wire.
So you have 2 separate circuits
Key switch---------fuse 24-----------clutch/neutral switch-----------Starter Relay------Ground ??
50amp fuse--------Starter relay------------starter motor-----ground