Prior to the fuse blowing, it never went to four by itself?
Fourth floor is top?
Will it run normally after it gets to four?
Do doors cycle when it gets to four?
Have you, just prior to, or after the fuse blew, removed and replaced any of those delicate Midtex ice cube relays?
Sounds like a selector problem...either floor relay or bad latch relay. Step up/DZ optical inductor could be bad too. I recall a stepper card in the controller, and some floor level sensor card in the COP.
Caution: When removing and reinserting those Midtex ice cube relays....you’ll never know if you’ve bent a contact pin until your trouble gets worse...good luck.
