0 ohms is not infinite, it's the opposite of infinite!

The FCM is right there on the fender wall, the cable from the fan connects directly to it.

The test is simple: unplug the fan and, using clip leads, etc, connect it to the battery directly - if the fan runs, the motor is fine.

A completely failed FCM will light the low coolant/radiator light. A partly failed FCM will not light the light and won't run the fan, either.

The 50 amp fuse is in the little square "engine fuse block" next to the battery. One 50A goes to the Pulse module and one to the FCM, the 200A feeds the rest of the car.