Chevrolet Repair: poor airflow from dash vents, vacuum motor, dash vents

Question
HI TOM,
I HAVE BOTH A 99 SUBURBAN AND A 95 TAHOE WITH THE SAME PROBLEM, VERY LITTLE AIRFLOW FROM THE DASH VENTS. THE BLOWER MOTOR IS SCREAMIN BUT POOR AIRFLOW (TEMP CHANGES ARE GOOD) REPLACED EVAP ON TAHOE (WAS LEAKING AND CLOGGED WITH DEBRIS) NO CHANGE. SUBURBAN JUST STARTED DOING THIS. COULD THE BLEND DOOR ACTUATOR BE THE PROBLEM OR POSSIBLY THE AIR FLOW ACTUATOR BE THE PROBLEM??? REAR A/C ON THE SUBURBAN WORKS GOOD, SYSTEM PRESSURES GOOD.

THANK YOU
A.J.HAJDUK

Answer
GOOD DAY A.J. YOU ARE CORRECT IN YOUR THINKING,THE BLOWER MOTOR ACTUATOR DOOR IS NOT OPENING ALL THE WAY..THIS IS CONTROLLED BY ONE OR TWO THINGS [VACUUM MOTOR] OR [ELECTRICAL MOTOR.]I HAVE FOUND MANY OF THE ACTUATORS WHERE THE PLASTIC GEARS STRIP OUT AND THEN WILL GET STUCK IN ONE POSITION..DROP THE LOWER SECTION OF THE DASH AND MANUALLY MOVE THE DOOR BY THE BLOWER MOTOR. IF AIR STARTS MOVING YOU FOUND YOUR PROBLEM,MOVE THE CONTROLS AND SEE IF THE DOOR STARTS TO MOVE OR TRIES TO MOVE IF SO YOU KNOW IT IS RECIEVING A SIGNAL TO DO SO. IF NO CHANGE IS FELT YOU MAY WANT TO REMOVE THE BLOWER MOTOR AND MAKE SURE THERE ARE NO LEAVES OR MOUSE NEST IN IT..THE TAHOE THAT JUST HAD THE EVAPORATOR REPLACED THIS MAY HAVE A BINDING DOOR...IN ANY EVENT THE LOWER DASH NEEDS TO BE REMOVED TO CK FULLY...LET ME KNOW HOW THIS GOES AND GOOD LUCK TO YOU,,,TOM..