Two Switches on the Manual Transmission
 

There are two switches on top of the 5-Speed. One (Driver's Side) is the backup light switch. The other (Passenger's Side) is described as a "1st/2nd Gear Switch" in the parts diagram. What does this switch do? ECU input of some sort?

Its the neutral switch. The 1st/2nd Gear Switch is only available on the RX-7 FD tranny.

Yup. Neutral.

It is wired in parallel with the upper clutch pedal switch, and goes to the ECU and the cruise-control computer. If the clutch is depressed or the transmission is in neutral, cruise control is deactivated. I'm not 100% certain what the ECU does with this signal, I assume that it is read by the idle code.

Thanks guys. That makes a lot more sense.