I tried to "hot wire" the fan by jumping one of the small wires to the main wire that ran to the battery post and grounding the other main wire, but no luck. I get a small spark that jumps when I hook up the main wire but the fan doesn't make a noise at all. It never smoked either. I'm pretty sure it is the fan. Mine is the one that doesn't have to have the control box. The fan spins free and I don't see anything wrong with it externally. Looks brand new really. I guess it would have to be that internal module made into the shroud the or the motor. Any ideas on how to test that, and are those replaceable? Cost effective to just buy a new one of Flea-bay?