What type of sensor is this? Is it a mechanical limit switch type sensor, is it a hall effect proximity sensor or is it something else? Also, you mentioned the sensor sweep was 4.5 - 1V. Does that mean that the sensor is outputing 4.5V normally and then it drops to 1V when the clutch throw-out arm moves or vice versa or what? What is the input voltage of the sensor? 12V, 4.5V or something else? During times when you want to bypass this sensor, how would that be done? Would you do it with a button or switch in the passenger compartment or by another method? You need to provide some more details about what it is exactly you're trying to do.