If the fan isn't working, yeah... I'd have to say I think that's the problem.

You said the fan motor is fine, all fuses and wires look good but the fan doesn't come on?

My guess is the relay (on the electronics bank by the battery) isn't telling the fan to come on. The temperature sensor could be faulty too.

Best thing to do is look at the owners manual to find out which relay you need to be looking at then see if there's any obvious damage such as burnt marks or melted plastic. You might be able to test this theory by using a relay from a nonessential system in the car and if it turns out the fan comes on when you put a relay in that's what you need to replace. Assuming the engine is hot and the relay is the problem you wouldn't even have to have the engine running to see if the fan comes on as it should upon substituting another relay.