The replacement was very easy and only took about 15-20 minutes. But in looking at both new and old sensors, it doesn’t appear that they have any kind of internal element inside of them that I can tell. It just looks like a cupped stainless steel flat rod. So I am theorizing that they function when damp clothing creates a conductive path between the two rods and the dryer’s circuit measures that conductivity and determined when it will shut off. If that’s the case then I don’t see how either of the old sensors could have been bad since they both had 0.1 ohms resistance from one end to the other (almost zero resistance). I’m guessing I could have just cleaned the old ones well and they probably would have worked.