1999 Honda Civic Fan won't come on

My engine cooling fan fails to work. I jumped the fan motor and it works fine, I tested the relay and it seemed fine but switched it with the relay on the condenser fan (which works fine and the relay was the same part #) and the condenser fan worked with both relays. The fuse is fine. I replaced the ECT sensor on the thermostat housing, drained and flushed the coolant and even went so far as to change the water pump. It still doesn't come on even though I drove the vehicle and the coolant should have gotten hot enough to close the ECT circut. I put a jumper on the connector that attaches to the ECT sensor and the fan comes on. My best guess is that the brand new ECT sensor is bad. What do you think?