In Larry's earlier post he mentioned listening for the fuel pump when you first turn the key to "On". Turn off the AC and the radio to be sure. You should hear a very light humming sound coming from the tank for 2-4 seconds. As you're not getting fuel out of the filter, and as I believe you've indicated no sounds other than clicking, I would guess that the pump is not getting power (or the pump is bad, but that is less common).
The '91 service manual is
here. Look at pages 11-8 and 11-98 thru 11-107.
Since you've already replaced the main relay, I would assume it's good for now. That leaves the pump, the pump relay, and the ignition switch.
You can troubleshoot the pump by giving it 12V through the resistor.
You can troubleshoot the pump relay like any simple relay. Give power to the terminals and check resistance to see if the switch closes.
If both of these check out, then it's down to the ignition switch.
None of this takes into consideration the alarm, as I have no idea how to go about troubleshooting that without tracing every wire between the pump and the ignition.