A/C problem - The 1947 - Present Chevrolet & GMC Truck Message Board Network

86lovelongbeds · 07-21-2012, 01:13 AM

Have been a member for a long time but dont post much, sold my 86 and bought a 08' GMC Sierra. Im getting older and its tuff to drive a truck without air now days lol.

Anyway my problem is when I turn my air on it blows cold out of both sides. If the air is turned to fresh air intake the air that is coming out of the vents is about the same pressure as it is if I turn on recirculate. I can hear the fan ramp up in RPM but the output to the vents is unchanged.

To the un-educated it seems that the blend door is stuck open but i'm not sure.

Any help would be appriciated.

**truckdude239** · 07-21-2012, 01:37 PM

could be had you checked the cabin air filter sounds like its stoped up

bighaas79 · 07-21-2012, 10:31 PM

Quote:

Originally Posted by truckdude239

could be had you checked the cabin air filter sounds like its stoped up

I'm pretty sure they quit with the cabin air filters back in like 03-04? Maybe someone else can chime in. However the pressure really shouldn't change. the speed of the fan doesn't change, what you are hearing is the change of air flow inside the airbox. If the fan is set on high, it doesn't go any faster. At high the fan gets system voltage, so faster than high is difficult to achieve.

**LEEVON** · 07-22-2012, 06:31 PM

That's correct, no more cabin air filters. You have a blend door actuator gone bad. Are you out of warranty?

07-21-2012, 01:13 AM	#1
86lovelongbeds Registered User Join Date: Jun 2010 Location: Poplar Bluff, Mo Posts: 24	A/C problem Have been a member for a long time but dont post much, sold my 86 and bought a 08' GMC Sierra. Im getting older and its tuff to drive a truck without air now days lol. Anyway my problem is when I turn my air on it blows cold out of both sides. If the air is turned to fresh air intake the air that is coming out of the vents is about the same pressure as it is if I turn on recirculate. I can hear the fan ramp up in RPM but the output to the vents is unchanged. To the un-educated it seems that the blend door is stuck open but i'm not sure. Any help would be appriciated.

07-21-2012, 01:37 PM	#2
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,237	Re: A/C problem could be had you checked the cabin air filter sounds like its stoped up __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube

07-22-2012, 06:31 PM	#4
LEEVON Moderator Join Date: Jul 2006 Location: Ozark, MO Posts: 4,888	Re: A/C problem That's correct, no more cabin air filters. You have a blend door actuator gone bad. Are you out of warranty? __________________ '20 Silverado Trail Boss ~ '17 Tahoe ~ '79 K15 Sierra Grande ~ '76 Blazer 2wd ~ '71 Cheyenne swb ~ '55 Pontiac Safari ~'50 3100 bagged ~ '80 Wife ~ Late model kids



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