Ford Probe Starting Problem

My 1989 Ford Probe suddenly failed to start when I turned the key -- no sound from the starter or starter solenoid. I was able to start the car by pulling it -- runs fine. I had the battery tested - battery is good. By-passed the starter interlock switch on the clutch pedal - still no start. I have a poorly written shop manual that tells me to test the starter solenoid, but getting to the solenoid is almost impossible. Before I resort to knuckle mashing, I wanted to see if there could be anything else I should check. Does this car have any kind of starter relay before the solenoid or other kind of interlocks?
Also, what are the four wires to the starter interlock on the clutch pedal for (my manual only shows two) :?