The engine cooling fan system is terribly simple - as is, it sounds, the "mechanic" you took the car to.

I WISH basic electrical / electronic troubleshooting was taught these days, but it is not.

THe FCM is powered by that 50A fuse. There is a comm link from the FCM to the PTCM consisting of one wire. The PTCM and FCM constantly handshake. If these handshakes quit due to a bad FCM, the PTCM will light the little radiator looking yellow light on the left end of the instrument panel - you can't miss that light. If that light is not on, you either have a bad fan motor or bad PTCM. If the FCM is really bad, the PTCM should light the light.

I'm really thinking the fuse was blown because the old fan motor was bad. You went out and got a new one, replaced the fuse, and all should have been ok.

Either you bought a bad fan motor assembly, or it is not plugged into the harness coming from the FCM.