I am not too familiar with exactly how an electric cooling fan works. If I have it right, there is a switch in the block near the starter. When the motor reaches temp, the switch sends a common to ground, completing the circuit to the fan relay, turning on the fan. I'm not sure if this is correct or not, but it's what I came up with. Mine works intermittently. I replaced both the switch, and the relay, no change. I now have it "hotwired" so the fan runs anytime the key is on. This may not be right, but it's better than being 40 miles from home, and having the fan quit. Is there something more I should be looking for? Thanks Greg