1999 Ford Taurus • 3.0L V6 FWD Automatic • 200,000 miles

Car drove home fine, next morning, nothing. New battery. Starter verified by engaging with jumper wire to battery. New ignition switch. Replaced starter relay. Removed harness to transmission position sensor and tried to bypass using a jumper wire between power to relay (pin 12) and power on start (pin 9). Tried again jumping pin 12 with power when running (pin 10). In the latter configuration assuming the car 'thought' that it was already running so would not engage the starter I also jumped the starter with key in on possition and the engine cranked but would not fire. Something still seems to be preventing the plugs from firing even when the transmission sensor is bypassed. Under all circumstances the car will not even try to start. No more ideas as to what to check next.
June 3, 2014.

Try resetting the security system, if no manual check online.

Jun 3, 2014.