Low air flow from vents

1990 GMC SIERRA
207,000 MILES • V8 • 2WD • AUTOMATIC
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ASH3MAN
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I have a 1990 gmc Sierra. The air flow from the vents is low. Installed new blower and charged ac with r134a. The accuator on the left side of vent system by gas pedal is working,defrost works,flow from floor to dash works.
Jul 23, 2011 at 6:53 PM
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HMAC300
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thinking that the blower works on all speeds then this could be an actuator problem or your high blower relay is bad. that should be by the blower. the actuators are in the htr box and you need to check if theya re working. that can direct the air as well asheat/cool. but check your relay first and your switch as it may not be giving the power you need to go on faster speeds. the pic of the actuator is generic
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Jul 23, 2011 at 7:40 PM
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ASH3MAN
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The blower works on all speeds and it sounds like a big rush of air going in to the blower box just not a lot coming out of vents.
Jul 23, 2011 at 10:14 PM
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HMAC300
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check your acutators then, check for a vacuum leak as yours may be run by vacuum.
Jul 24, 2011 at 1:07 AM