The parts have been in a long time, just haven't been used much because it hasn't been on the road yet, the first controller that was adjustable did what it was supposed to but I had to put twisting pressure on the circuit board to get it to work.It was bad right out of the package. I didn't try to return it because it had been sitting on my shelf for over a year before I installed it. That's when I went to just a simple on/off sender. It has one spade coming out of it that grounds when it warms up and opens when it cools down, and I have that hooked to the ground wire on my relay. It seems like the problem is that it measures the block temp more than the rad.When the first batch of cold water comes to the block to cool it off after the thermostat opened, the fan stays off when it should be cooling the hot water that just came out of the engine to the radiator.Maybe I ordered one with 200 on 175 off, not sure but it isn't enough. If i to order another on off switch, what would be good temps to go with, 190 on 165 off ? Otherwise I was looking at adjustable ones with a probe in the rad.