a/c or heater on 2003 GMC Safari

a/c or heater not blowing air from front vents. you can hear the blower motor, but can barely feel the air. high setting also not working. only med. and low work. please help.

4 answers 1 comment
Is it possible the air is coming out of the windshield vents all the time? That would indicate a problem with the vacuum supply from the engine to the A/C control assembly. As far as the blower motor goes there is a the high speed works through a relay which is part of the blower motor resistor assembly. Two possible causes would be the switch or the resistor assembly. Please have the blower motor system diagnosed to find the cause of your problems before replacing any parts.
The air IS only coming out of the windshield vents in my car. What do I do now?
where does vacum line conect to engine
The vacuum lines feeding the diverter switch get brittle and break. If you don't hear a slight vacuum sound when you switch from defroster to vents, check the vacuum lines for cracks or leaks.
the fan barely blows in front