Is it possible that I can use an external temp sensor (say one that I can connect to a bolt) for surface temperature, with a buzz horn of 160-180?F. With little to no harm to the motor
Sure you can, but I'd want it to go off a little warmer than that, like boobie mentioned. I always thought 200 was too high though. There was just a thread somewhere around here the other day about someone doing just what you want to do. Good luck!
