Short answer, I'd bet it's in the bulkhead connector. You do have an FSM, right? Do you have power to everything else, lights, radio, heater, etc? If so you have power to the ignition switch. Look on the wiring diagram and see if you have power to the starting conductor on the ignition switch when you turn the key to start. This would be on the passenger compartment side. If you do, the switch is good and the wiring to and from the switch is good. Then go to the engine compartment and see if you have power on the same lead when you turn the key to start. My bet is you won't but that is only a bet at this point.

Forgot to ask, manual or automatic? If automatic you could have a problem with the neutral safety switch wiring and have the ignition switch side of it all perfectly functional.