REPLACED EVERY MODULE IN THE HEATER SYSTEM IN MY 05 GMC SIERRA SEVERAL TIMES, AND SO HAS JUST ABOUT EVERYONE ELSE I KNOW WHO OWNS ONE. NOW MY WIRING HARNESS BURNED WITHOUT BLOWING ANY FUSES. GM SHOULD HAVE A RECALL ON THIS, AND FIND THE PROBLEMS, AND FIX THEM, BEFORE EVERYONE WHO OWNS ONE GOES BROKE REPAIRING THEM. *TR