It's the cylinder or the key is worn down. Once I ran into a problem where the cover on the wafers rose up and was hanging in a slot in the cylinder housing, but the key would turn but not far enough to start the car. But if it wont turn, I would suspect the key or something sticking inside the lock.
sounds like the ignition control module
remove the plastic coverings from around the steering wheel (3 screws on the bottom), turn the ignition to the running position and take a small screwdriver and move the pin up on the bottom of the ignition cylender and pull it out. dunno if my explanation is detailed enough... oh well.
I would "start" with the ignition key switch/cylinder in the steering column.The "Related Questions" below writes about it on the Taurus/Sable, but I'm extremely confident it's relevant to most Ford products...
Possible switch or lock cylinder
Unplugging the coil wire and not grounding it, yes that can damage the coil.
The temperature should be 195 degrees.
It probably is the key switch.
there is no such thing as an exhaust coil. the ignition coil is the cylinder shaped thing that has a spark plug wire running to the center of the distributor cap
where is the daytime running light relay located on a 2002 chevy cavalier
If it runs fine, probably an Ignition Cylinder problem If it runs kinda funny, probably it's just "dieseling"
190F
Could be a bad starter solenoid (return spring not strong enough to disengage) Could be a bad ignition switch (does it release if you shift to "Drive"?)