http://wright-here.net/cars/rx7/manuals.html
Download the manual for your car. Trace down your wires, they may have broken and fell off?. Extend them if necessay and hook them back up. If the plug is nowhere to be found, once you find the wires, you can probably locate another plug at an auto parts store. It is a fairly common plug, or use female spade connectors as a temporary fix until you can locate the correct plug.