Flat resistance for blower control unit of automobile air conditioner

A blower control unit of an automobile air conditioner, comprising:

• a substantially flat resistance element comprising a porcelain enameled metallic substrate including a head portion having at least one surface, and a resistance circuit printed on the at least one surface of the head portion, the resistance circuit including a plurality of resistances electrically connected in series;
• connecting means for electrically connecting at least one of the resistances of the resistance circuit to a fan motor circuit for driving a fan;
• a fan scroll including a top wall, a bottom wall and a spiral side wall with a nose portion, the side wall joining the top wall to the bottom wall to surround the fan, the top wall, the bottom wall and the side wall defining a blowout opening;
• and
• mounting means for mounting the porcelain enameled metallic substrate to the bottom wall so that the head portion of the substrate is within the fan scroll in the vicinity of the blowout opening at an angle from -30.degree. to +20.degree. to part of the side wall closest to the mounting means, the part of the side wall facing the nose portion of the side wall.