When you said rapidly clicking relay, I immediately thought of a ECM problem. For some reason on the 92-93 trucks a capacitor fails and creates a no start condition when under 55 or so. I've had 2 fail like that on my 92. Easy to test:
1.turn ignition on and see if check engine light comes on. it should as part of the test sequence of the ECM
2. Can also warm up the ECM with a hair dryer or similar- if it starts right up, you found the problem

Otherwise, a loose/corroded connection is next