Does anyone know how I can tell if my sideview mirrors heat up. I just went to the Pik A Part and took 2 side view mirrors off an 84 Supra to replace mine (I have an 85). My friend said there may be a slight wiring difference between the 84 and 85 because the 85 mirrors heat up. Only I have owned my car for many years and have no idea whether mine heat up or not, and if they do I have no idea how to activate it. Does anyone know. And if so, will the 84 mirrors work.'Cause they really LOOK the same.