what is a relay fuse for in a lincoln ls 2003

A relay fuse is a fuse that will blow like any other fuse to prevent overheating in wires or prevent electrical damage to a unit... in this case a relay... from too much electrical current (amperage or amps) flowing into it. The relay is a device which takes a small current which can safely pass through a switch that a person can touch, and the relay then uses magnetic connections to pull 2 or more heavy duty wire connections together to allow massive current, which is dangerous for people to be around,to flow. Much like a key in your ignition. It takes a small voltage and small amperage for you to turn the key then sends it to the ignition coils which kick up the voltage and amperage to deadly levels in order to start your vehicle. There are several relay fuses in the vehicle.