There are two plugs that connect to the clutch switch.
The brown plug is the clutch safety/starter interrupter circuit. Red wire with blue stripe. This is for the starter circuit and the car will not start unless this circuit is closed. On the AOD cars there is a jumper (pictured above) and on the 5-spd cars it plugs into the clutch switch and closes with the clutch pressed in. THERE IS NO NUETRAL SAFETY ON 5-SPD CARS. The NSS is on the AOD only, and gets jumped out on the 5-spds in the Reverse harness under the car.
The clear plug is the NGS or Nuetral Gear Switch. It's only purpose is to inform the ECU if the trans is in gear for the purpose of code dumping and it may affect idle strategy a bit (i haven't confirmed this in the ECU code yet). It's wired in parallel with the plug on the top of the T5 that most people incorrectly think is the NSS. They work together to tell the ECU when the car is in neutral by way of clutch in, or T5 in N, for the sole purpose of code reading/idle and does nothing with the starter circuit.
AOD cars do not have the correct plug in the trans harness for the NGS that plugs in to the top of the T5. What
sometimes happens is that the car will have a hanging idle when sitting at stop light with clutch out, and trans in neutral. Pressing the clutch in sometimes gets the idle to drop. I've recommended folks just unplug the NGS plug from the clutch pedal and stick a 5A blade fuse in to see if that solves the hanging idle issue.
As for cruise control. See this thread and see if it answers any questions you have or respond in there if you have additional questions. C220 on your diagram comes from the cruise control servo in the fender. It pokes through a grommet in the far left corner of the dash where the outer fender is. C221 is in the vehicle harness somewhere. All fox models will have C221 existing
Done a little research into this and figured what I learned should be put into a thread and added to the tech sticky. As you can imagine, nobody really gives much thought to cruise control on these cars, so many searched threads had dead ends. So many this will help someone out down the road...
stangnet.com
Heres the cruise servo. The plug to the right would be C220. You can see the grommet that would poke through the firewall middle of that wiring harness.