It is the master switch that get not real hot but you can feel it.It is the one that caught fire and the fan switch also ,Had to pour water on it to get fire out.Melted the upper a/c vent.The original wiring harness.I pulled it out when I did the frame off and rewrapped it but I guess it could ne too old like me.Almost to the point to change to a Vintage Air unit.Thanks for comments