I have this temperature sending unit from my 72 El Camino. It is factory for the HOT idiot light. I want to know what is the temp that these work at.....190.....200...210 degrees?? Here is a pic of it.
http://www.mustangmods.com/ims/u/214/217/62706.jpg
Thanx,
Brian

Much higher than those...my Chilton manual for '64 to '71 cars says around 250*F. Don't be so quick to call them idiot lights...Modern airplanes have audible warnings and warning lights and indicators, less modern airplanes have warning lights and indicators, and truly old airplanes have just the indicators. For those old airplanes they have a full time guy to monitor engines and other systems while the drivers are doing their thing.