Other guys have covered this, but I'll re-iterate what I've done.
Been through this a few times, including last weekend where somewhere in my Transmission wiring (aftermarket) I had a short.
My Symptoms : Car would crank, slight fuel in rail. No Start
Check :
Under dash fuse box (look for PCU BUS) (PCU Bus threw a fuse. I disconnected TCM, FUSE Didn't blow. Short somewhere in TCM Wiring)
For you:
Then check under hood relays and fuses.
Test the horn to make sure that relay is good (Now use it for the starter relay, ignition and fuel pump relay) You can swap both of those relays to the horn position to make sure the horn still works. If that still doesn't work then move to sensors.
When my TJ had a bad CPS, I had a NO BUS illustrated on the dash. No crank, no fuel etc...
Useful images attached... (EDIT - Attached Wrong Ones)
You need to look at pages 14-26 - 14-51 in the FSM.
Search for the following file in google : 00tjee.pdf