mortten

2014 Sierra 1500 SLE with auto climate control. Starting the truck and driving it perfect air flow out all vents. After driving about 15 minutes there is hardly any airflow through any vent. Scan tool shows no code. Shows blower motor requested speed and actual speed at 100%. You can hear the blower going full speed. Shut it down and wait 20 minutes it works fine for 15 minutes then loses flow. Coolant is full. Does it on both manual and auto. At a loss.