This would be best asked in tech.
Best to just get the wiring diagram for the car, from a Chiltons, Ford manual, Autozone site, etc, to see which circuits are hot all the time and which are hot in start or run.
Or just check with a meter.
There really are not relays that control the fuse box. Most circuits are just hot or powered by the key. There may be some power circuits from relays that run through and are fused in the fuse box, but you need to go circuit by circuit. Most of those will have the fuse before the relay anyway. Note there are also several fuse links in various power wires in the car.
What exactly are you looking for?
