my shelby dakota uses electric fans, computer controlled. the fans died, and the replacement uses a radiator fin probe, to operate. it goes into a control box that allows me to set the high/low, and it works fine. the probe is up top, near the radiator inlet. a second wire runs to the a/c compressor to run it whenever the a/c is on, but on a non-a/c car, you could use this extra circuit for a manual over ride. i've put 15K miles since the conversion, and no issues.