96 Cherokee starts but won't run

I have a 96 Cherokee Sport that has developed a little problem. The engine will start, but will not continue to run when in the "ON" position. In fact, nothing works with the key in the "ON" or "Accessories" positions. Dome Light and headlights work fine. For about a week before, when I started the car, instead of letting the key go back to the "ON" position by itself, I'd often have to move it a little more. Once it was running on it's own, I'd be able to move it back to the correct "ON" position. I've done some looking around, and have found two common problems. One is a relay, and the other is the ignition module. Has anybody had this problem, and if so, what was the solution? If it's the relay, which one would it be? Thanks, Wes