F73 is the fuse that should blow to protect the rest of the electronic systems if the mast wiring loom is shorted out, the F73 fuse is very important as you have found out.

The RRE will try to protect itself when a serious electrical fault is detected, it can even turn off individual circuits / or even put the truck in to limp home mode.

Normally switching the truck OFF or better yet pulling the battery isolator with the truck powered up & then powering it back up after a minute will allow it to its self diagnoses & if the fault has gone it will reactivate the circuit in question.