From this manual, I learned how the ICM, Battery Saver, Delayed Accessory, and Rear Defroster are related:
Ford Explorer 2003 Workshop Manual (Page 5 of 17)
Based on this and my experience with the electrical nightmare in my Explorer, I have worked out the following:
The Battery Saver Relay (cabin relay #5) supplies power to the ICM circuitry for gauges and Odometer, and this ICM circuitry in turn supplies coil power to the Delayed Accessory relay (cabin relay #3 - power windows, dome lights, radio) and the Rear Defrost relay.
Cabin Fuse 17 supplies power to the Battery Saver relay (load side) and the Delayed Accessory Relay (coil side) and thus (directly or indirectly) to the Instrument Cluster Module (gauges and Odometer), power windows, dome lights, radio, and glove box light.
Cabin Fuse #21 supplies power to the Instrument Cluster (not gauges or Odometer) and the flasher coil. If your turn signals work, this fuse is good.
If fuse #21 and #17 are good, AND your Instrument Cluster gauges and Odometer are offline, AND Rear Defrost doesn't work, AND Delayed Accessories (power windows, radio, dome lights, etc) are not working, your problem is either with the Battery Saver relay itself, the relay circuitry, the Instrument Cluster wiring to the Battery Saver, or the Instrument Cluster itself.
When checking the Battery Saver (#5 relay), be sure to test the relay itself, and the relay circuit coil voltage, load voltage, and ground.
If you've blown Fuse #17, you definitely want to check the electrical current draw on the battery after replacing it. My Explorer was pulling 1.4 amps off the battery (with the key off) due to a shorted out battery saver relay, which was causing my Instrument Cluster Module to power cycle repeatedly, which was causing my Delayed Accessories to turn off and on.
As mentioned in many posts above, there are other common culprits for short circuited wiring and they should also be checked if there is high draw on the battery. For reference, my Explorer was drawing 0.024 amps after fixing the shorted Battery Saver relay.