For clarification, my bypass switch is wired in parallel with the otter switch so the otter switch works as it used to or I can turn on the bypass and the fan stays on. It made a huge difference in the fan switching on and off all the time and the car runs a lot cooler on hot days. My bypass switch activates the relay.
My theory about the constant fan cycling is that with the otter switch at the bottom of the radiator, it activates when the water in the rad gets hot, the fan comes on and cools the water flowing through the rad, that cool water shuts the otter switch off and the water flowing into the rad heats it up again starting the cycle over. I think putting the fan switch at the bottom of the radiator is a poor design for this reason. If I put in an aluminum radiator in the future, the fan switch is going to be in the top tank.
