99 Chevy Suburban C1500 AC question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

shultzee13 · 05-31-2013, 12:18 PM

Is it common for the blower motor to be extremely loud but no so much air blowing out while the AC is on it's highest setting?

The sound doesn't match the output.

I've checked the blend doors and all the servo motors are operating correctly. It does have rear air but I notice no difference with it on.
It blows cold. Just not hard.

Doesn't move your hair LOL

DnHolland · 05-31-2013, 12:41 PM

Does the air flow increase in the heat position? Does it start out blowing normal and progressively get less? If you refrigerant level is low it can cause the evaporator to ice over restricting air flow. They did not have cabin air filters in 99 so it can't be that. If the truck is used in the field(I notice you're from Texas, we have this problem here) the evaporator could be clogged with dust, grass, etc. You may have to pull the blower to look in there and see. I have seen some so stopped up that I had to remove the evaporator and clean it with coil cleaner. Make sure if/when you drive off road in dusty dirty conditions run the a/c in recirculate mode. That way it pulls air from inside.

shultzee13 · 05-31-2013, 12:47 PM

No sir. Does not get worse. Same force all the time. Just doesn't blow hard. Doesn't change on heat position. I bought it used. I have no idea how the previous owner used it. But I don't use it in the field. Just normal road driving.

You suggest I pull the blower motor cover and see or the evaporater or both>?

DnHolland · 05-31-2013, 12:57 PM

I would pull the blower first. Nothing beats a visual inspection and that is the easiest first step. You could have a broken fan blade(s). I think you can see the evaporator with the fan removed(you may need a mirror and flash light). To remove the evaporator, you have to take the entire dash out and remove the heater/a/c box assembly. It's about a 7 hour job. Do you have water coming out of the condensate drain?

shultzee13 · 05-31-2013, 01:00 PM

No sir. No water coming out.
Posted via Mobile Device

DnHolland · 05-31-2013, 01:09 PM

I'm hoping the fan is broken but, I bet the evaporator is plugged up.

shultzee13 · 05-31-2013, 02:09 PM

Are you asking if water is draining out of the firewall port? Yes water comes out of there. It doesn't swish sound when I turn corners either. I drilled a hole in the evap box and shot cleaner down in it. I did not notice a difference. Maybe I'm just used to my wife's AC in her 2012 scion but the burb just doesn't blow very hard at all.
Posted via Mobile Device

05-31-2013, 12:18 PM	#1
shultzee13 Registered User Join Date: Jan 2012 Location: Tyler Texas Posts: 223	99 Chevy Suburban C1500 AC question Is it common for the blower motor to be extremely loud but no so much air blowing out while the AC is on it's highest setting? The sound doesn't match the output. I've checked the blend doors and all the servo motors are operating correctly. It does have rear air but I notice no difference with it on. It blows cold. Just not hard. Doesn't move your hair LOL

05-31-2013, 12:41 PM	#2
DnHolland Registered User Join Date: Oct 2009 Location: Middle Tennessee Posts: 28	Re: 99 Chevy Suburban C1500 AC question Does the air flow increase in the heat position? Does it start out blowing normal and progressively get less? If you refrigerant level is low it can cause the evaporator to ice over restricting air flow. They did not have cabin air filters in 99 so it can't be that. If the truck is used in the field(I notice you're from Texas, we have this problem here) the evaporator could be clogged with dust, grass, etc. You may have to pull the blower to look in there and see. I have seen some so stopped up that I had to remove the evaporator and clean it with coil cleaner. Make sure if/when you drive off road in dusty dirty conditions run the a/c in recirculate mode. That way it pulls air from inside.

05-31-2013, 12:47 PM	#3
shultzee13 Registered User Join Date: Jan 2012 Location: Tyler Texas Posts: 223	Re: 99 Chevy Suburban C1500 AC question No sir. Does not get worse. Same force all the time. Just doesn't blow hard. Doesn't change on heat position. I bought it used. I have no idea how the previous owner used it. But I don't use it in the field. Just normal road driving. You suggest I pull the blower motor cover and see or the evaporater or both>?

05-31-2013, 12:57 PM	#4
DnHolland Registered User Join Date: Oct 2009 Location: Middle Tennessee Posts: 28	Re: 99 Chevy Suburban C1500 AC question I would pull the blower first. Nothing beats a visual inspection and that is the easiest first step. You could have a broken fan blade(s). I think you can see the evaporator with the fan removed(you may need a mirror and flash light). To remove the evaporator, you have to take the entire dash out and remove the heater/a/c box assembly. It's about a 7 hour job. Do you have water coming out of the condensate drain?

05-31-2013, 01:00 PM	#5
shultzee13 Registered User Join Date: Jan 2012 Location: Tyler Texas Posts: 223	Re: 99 Chevy Suburban C1500 AC question No sir. No water coming out. Posted via Mobile Device

05-31-2013, 01:09 PM	#6
DnHolland Registered User Join Date: Oct 2009 Location: Middle Tennessee Posts: 28	Re: 99 Chevy Suburban C1500 AC question I'm hoping the fan is broken but, I bet the evaporator is plugged up.

05-31-2013, 02:09 PM	#7
shultzee13 Registered User Join Date: Jan 2012 Location: Tyler Texas Posts: 223	Re: 99 Chevy Suburban C1500 AC question Are you asking if water is draining out of the firewall port? Yes water comes out of there. It doesn't swish sound when I turn corners either. I drilled a hole in the evap box and shot cleaner down in it. I did not notice a difference. Maybe I'm just used to my wife's AC in her 2012 scion but the burb just doesn't blow very hard at all. Posted via Mobile Device



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