HEATER AND RESISTOR REPLACEMENT on 2005 GMC Sierra 1500 HD

WE DID BOTH, PUT IN A NEW BLOWER THATHAS A LIFETIME WARRENTY , REPLACED THE RESISTOR TWO TIMES , ALSO CHECKED
FAN SWITCH. WAS OK AND WORKED ON ALL SPEEDS, AFTER ALL THIS ,FAN ONLY WORKED ABOUT A WEEK. WHAT NOW ????

1 answer
Possibly a defective blower motor