Dodge Ram Low Air Flow from AC Vents
November 15, 2009 12:06 pm Air Conditioning, How To Auto Repair 
© DenLorsTools.com Summary: This article is about Dodge Ram pick up trucks that have a common air-flow problem with the HVAC (Heating Ventilation & Air Conditioning) system. The problem causes little heat (or AC depending the time of the year) to flow through the vents. The blower fan can typically be heard with no abnormal sounds, although no air seems to be making it out of the vents. We go over parts that need to be removed to gain access to replace a common failed component.
A common problem for the Dodge Ram pick up truck is to have low airflow even though the blower fan can be heard loud and strong. Usually the problem is because of a broken fresh air door – AKA recirculate door. The fresh air door is located behind the glove box area. What can happen is the door can break and fall down covering the blower fan, essentially sealing off all air-flow. That’s why the blower can sound normal on all speeds, but little air can be felt from the vents. The broken door below shows the point at which the break is common.
8/08/2022 Update * Since this article was first written there has been a door produced, that can be installed without removing the dash. We don’t sell it anymore however, heatertreater.net may have this available still. The replacement door has steel construction instead of the weak composite material used from the factory. So it’s built to last. The kit works on 2002-08 Dodge Ram pick up trucks. Installation is done after removing the glove box – the dash does NOT have to be removed. Contact heatertreater.net for more information.
In the image below, the x’s mark most of the trim pieces that need to be removed to gain access to bolts which hold the dash. One that is not marked is on the top of the dash, it’s the large trim panel which is not visible in the picture. This can be an easy job to do at home since the air conditioning system does not have to be discharged. In fact nothing on the firewall side has to be disturbed.
Note that the steering column is unbolted and allowed to drop down and is not unbolted at the steering coupler. Undo the stop light switch to prevent stress on the wiring when the dash is swung.
Below the new door assembly can be seen back in position and the dash can now be re-installed.
Reverse the removal process of the securing bolts and trim panels and the job is done.
The tips in this article are very basic and NOT intended to be a complete guide for servicing your AC system. Please refer to a repair manual for further instructions.
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dennisb - Auto Tool Sales :
Date: August 10, 2013 @ 3:39 pm
Typically there are three doors in the HVAC case. Fresh air, blend and mode. If a system has dual (split zone) there will be a fourth. The easiest one to get to which can be done without a major job, is the fresh air door which is what the article is about. We don’t sell any of the other doors because they they don’t fail as often and they are not what I consider a “do-it yourself” job. The door we sell for the fresh air door replacement is a do-it-yourself type repair that has saved our readers a lot of money while improving the design and strength.
James :
Date: November 3, 2013 @ 11:49 pm
Just had blend and all actuators replaced on my 2006 mega cab diesel and I still have the problem of air blows harder on driver side than the passenger side any ideas????
dennisb - Auto Tool Sales :
Date: November 4, 2013 @ 7:07 am
James, it could be a control head issue or an air duct with a leak… It would have been obvious if the door was broken so the shop would have been able to tell you if the door was the problem or not. Also, the repair shop can check to see if there’s any codes stored for the HVAC system which may lead to the problem. Could also just be something blocking the duct work. Good Luck
James :
Date: November 6, 2013 @ 7:47 am
I took it back to the dealer and they pulled it back apart again they said there is a screen in the duct system that was clogged from old material off of old blend door, they found a service letter on it and removed the screen according to service letter and problem is fixed air blows hard on both sides now
Phil :
Date: December 24, 2013 @ 10:48 am
Have a dodge 2500 bighorn diesel. Am getting heat out of passenger side and cold out of drivers side with heater on. Can you give me any suggestions on what to check
dennisb - Auto Tool Sales :
Date: December 24, 2013 @ 12:51 pm
Most likely a broken blend door- read below for more on the doors.
Typically there are three doors in the HVAC case. Fresh air, blend and mode. If a system has dual (split zone) there will be a fourth. The easiest one to get to which can be done without a major job, is the fresh air door which is what the article is about. We don’t sell any of the other doors because they they don’t fail as often and they are not what I consider a “do-it yourself†job. The door we sell for the fresh air door replacement is a do-it-yourself type repair that has saved our readers a lot of money while improving the design and strength.
Phil :
Date: December 24, 2013 @ 2:03 pm
Thank you, I will start with that
Josj :
Date: January 30, 2014 @ 3:20 pm
I have a 2002 Dodge Ram 1500 Quad Cab and the heat and A/C work fine and the air is circulating properly. My issue is that I can only get heat on max settings and on non-max settings the air is cold. Can the recirculating door cause this problem or is a blend door or mode door 1/2 issue?
dennisb - Auto Tool Sales :
Date: January 30, 2014 @ 3:36 pm
It could be normal if the ambient (outside) temperature is extremely cold. Think about what the MAX (recirculate) is doing. When it’s on recirculate the system is heating the air that is circulating in just the cab. If it is not on recirculate, the system has to heat the outside air that is entering. Not a big deal unless it’s near or below freezing outside. Good Luck.
jeff :
Date: February 9, 2014 @ 12:57 pm
2006 Dodge Ram 2500. The defrost blows cold while the floor blows hot air.
dennisb - Auto Tool Sales :
Date: February 9, 2014 @ 3:52 pm
Not related to the recirculate door.
jeff :
Date: February 9, 2014 @ 3:54 pm
Any ideas
dennisb - Auto Tool Sales :
Date: February 9, 2014 @ 4:10 pm
I would rule out the recirculate door and look at the other doors…
GTW :
Date: February 9, 2014 @ 4:22 pm
06 Dodge Ram 3500 QC,SB,Sat, Jake, Etc.
Just after my warranty expired my hvac fan started making a horrible noise. At that time of year I needed my defroster so just ran it on low until I could dig into it. I was thinking that a pencil or something had fallen down the defrost vent What I didn’t realize was that the fresh air door had broke and fallen against the fan causing a load on the motor and it burned out the overload relay and that left me with only the highest fan setting. (safety feature) I bought a new relay, installed it, (super easy) and pulled the motor/fan out. I used 2 hacksaw blades pushed the door back in place and wedged the blades up against the door to hold it. Been working for 6 years now with no problems. The dealer wanted 850.00 to fix.
L.T. :
Date: February 20, 2014 @ 2:51 pm
Having issue with poor air flow from vents in 06 Dodge 2500. Pulled blower motor and recirc. door was not broken but once I grabbed it to check it’s operation it broke. I removed then the broken door and re-installed the motor and still have poor air flow. Noticed when truck is idling that the blower motor speed occasionally increases then decreases rapidly. When selecting floor vent it seems to have decent air flow but poor out of the dash and defrost vents. The truck is used in farming conditions which consist of lots of dust so I’m starting to think the plenum box is full of mud/dirt? Also the surging of the blower motor speed is throwing me off a bit too. Any ideas?
dennisb - Auto Tool Sales :
Date: February 20, 2014 @ 6:41 pm
A little fluctuation in the blower speed is normal due to the varying demands on the electrical system; like when the AC compressor cycles on or off or other demands change for whatever reason. Many of today’s cars have cabin air filters but I don’t believe your truck has one. That means that the dirt and pollen could have been collecting on your evaporator core and could be restricting air-flow. Maybe you can remove the blower motor and access the evaporator. I know on some models you can get a peak that way. If you can see it and confirm there’s a lot of dirt collected on the fins you may be able to clean the evaporator. I’d use a garden hose being careful not to get anything electrical wet and recheck. We sell the recirculate door which is made of steel instead of the factory plastic. Having the door will always help when on recirculate mode. Good Luck.
bobp :
Date: March 11, 2014 @ 12:12 am
I have the dash out as explained and found bad recirc and bad mode 2 door. Unfortunately, I took much more apart before finding your post. I have so much I cant tell what position I left the HVAC controls in. I am going to replace 2 doors and need to know: do the actuators self-calibrate? I hate to put everything back and have the door orientation wrong and snap the plastic coupler or door.
dennisb - Auto Tool Sales :
Date: March 11, 2014 @ 6:37 am
Bob, yes they self calibrate. Good Luck.
geronb73 :
Date: April 11, 2014 @ 4:08 pm
Thanks for your post. I’ve been wondering why my air flow doesn’t blow well will check blower motor location when I get off for trap door…
thanks Geronb73
donchilito :
Date: April 13, 2014 @ 6:26 am
Any info on changing out the recirculation door on the 09 1500 crew cab? Can it be done by removing the blower motor as well? Thx
dennisb - Auto Tool Sales :
Date: April 13, 2014 @ 8:28 am
The door kit that we sell is for 2002-2008. You may be able to remove the door through accessing the hole behind the blower motor but that’s not a real fix. You will no longer have MAX capability which removes much more of the moisture in the passenger compartment and allows more efficient heating and cooling. Good Luck.
steve :
Date: April 23, 2014 @ 3:36 pm
I have a 1999 dodge and i am also getting little air and alot of noise even after putting a new blower motor in my truck. i am going to be replacing the dash and will have alot tore down so i am going to look into the door issue. do you sell parts for a 1999 dodge 2500? thank you for your time
dennisb - Auto Tool Sales :
Date: April 23, 2014 @ 4:43 pm
Steve, sorry we only sell the one recirculate door for the 2002-2008 Dodge Ram. Good Luck.
jimmycrackcorn :
Date: May 31, 2014 @ 7:00 pm
Hello Dennis.. Great writeup. Its exactly what I was looking for! However, I am in a some what different predicament. I need to replace the heater core & on top of that the lower housing of the hvac box, it’s clearly broken with some sort of plastic sheet welded/siliconed on. Model is a 07 2500 ST single cab 6 speed The scumbag dealer passed this problem along to me & are 2000mi away so I can’t really bring it back. I can’t seem to find any info on the lower box replacement or even a aftermarket part #. Do you know where I could find one?
Take care,
Matt
dennisb - Auto Tool Sales :
Date: May 31, 2014 @ 7:28 pm
Hey Jimmy, sounds like dealer only parts. May a salvage yard? Good Luck.
americanhotrod :
Date: June 3, 2014 @ 5:14 pm
I was fascinated to find this blog. Great info. I have a 2006 Dodge 1500 Mega-Cab and it recently started blowing warmer air on the passengers side than the drivers side. Once really moving, the drivers side is 42 degrees and the passengers is 62 degrees. driving around start and stop is 62 degrees and 82 degrees respectively. It seems like standing still the passengers side starts to cool better getting hotter under acceleration. I assumed actuator problem caused by a vacuum issue were the actuator won’t hold under less vacuum. Reading this, I’m wondering about need for Freon. What do you think?
MRR
dennisb - Auto Tool Sales :
Date: June 3, 2014 @ 5:22 pm
I’d always check the refrigerant charge first. Good Luck.
jimmycrackcorn :
Date: June 7, 2014 @ 6:14 pm
That’s what I was thinking, dealer only or junk yard. I’ve called around to a few “truck yards” but they all want me to have the part in hand, but that just isn’t do-able. Do you know if there were multiple styles of HVAC boxes for early 07? I know of the dual climate but mine is a single cab. They are making it sound as if there are more than two styles for early 07.
Also.. I wish I could send a pic for you to reference but here’s is what I’m thinking. I believe there was an accident were the box got smashed on the passenger side. The PO plastic welded something on there but didn’t realize the core got hit too & buttoned it all up with it leaking. The box doesn’t hold any sort of fluid, right? It’s all contained in the core, right? If I could get away with just replacing the core & just deal with the ugliness of the yellow plastic sheet weld I would be functional as the weld was to just hold the heated/cooled air in the box. Does that sound about right?
Thanks for your help, your doing a good thing here.
dennisb - Auto Tool Sales :
Date: June 7, 2014 @ 7:22 pm
As far as the different styles, you would need to check witha dealership that has that information in crash books or diagrams on their computer etc. But, I would probably just replace the core and seal up the case. That’s a s long as all of the modes for changing air direction and air mix function properly. Good Luck.
Paul :
Date: June 10, 2014 @ 5:55 pm
I have a 2004 3/4ton dodge ram seem to have water coming out air ducts not anti/freeze as first thought was heater core is there a condensate hose that could be plugged?
dennisb - Auto Tool Sales :
Date: June 10, 2014 @ 7:10 pm
Paul, yes. All evaporator cases have a drain the bottom usually that goes through the firewall. Look for any dripping water underneath the truck when the AC is running to help locate the hose. The drain may be completely or just partially clogged. I’d try a metal coat hanger and compressed air to free the clog. In extreme cases like if you park under trees a lot, there could be a lot of leaves in the evaporator case. Sometimes you can remove the blower motor to access and remove the leaves. Other times the entire evaporator case has to come out and taken apart in order to clean it out well. Good luck.
Alexander :
Date: June 14, 2014 @ 12:21 pm
I have a 2002 dodge ram 1500 and at the lowest or highest speed I have the ac on it still only blows from the bottom. At any speed the air barely comes out of the front vents. Not sure if I’m having the same problem as everyone else with the broken recirc door.
dennisb - Auto Tool Sales :
Date: June 15, 2014 @ 4:36 pm
The easiest way to see if the door is broken is to look behind the glove box and inspect it. The resistor may be faulty causing the blower not to work on all speeds. Good Luck.
MauiKimo :
Date: June 21, 2014 @ 1:06 am
you talk about the door failure, but mine works fine until I throttle up the vents close. release the throttle and the vents open again. I know it has to be a vacuum leak, but where would it be, inside the truck or engine compartment. I know the door is not broken, the truck is a 96 1500 with 5.2 liter motor and only 70,000 miles on it. Mahalo
dennisb - Auto Tool Sales :
Date: June 21, 2014 @ 9:30 am
This article is not on the older models like your 1996. Your problem does sound like a vacuum leak. Newer vehicles are more likely to have vacuum leaks in the passenger compartment because the heat can cause plastic to harden and break easier and there could be battery acid or other leaks that can damage vacuum lines. Your truck, being 18 years old, could have a vacuum leak anywhere, especially since the plastic can become brittle over time no matter if it’s in the engine compartment or not. I would start by checking in the engine compartment and following the line inside the cab. There could be a break in the line somewhere or there could be a bad diaphram in one of the actuators, causing a vacuum leak, that works a door. The control head could also have a vacuum leak. A visual check is the first step. Using a vacuum pump I’ve been successful finding leaks like that before also. On harder leaks to find I’ve used a smoke machine. The smoke escaping reveals the problem area. Good Luck.
Guy :
Date: June 21, 2014 @ 1:56 pm
Hello, I have a 2003 dodge 2500. The air is cold but not blowing hard through the vents even when the blower is on high. I checked the havac door and it works fine. Checked the blend doors seem to be working fine. I can’t figure this one out on my own, please help
dennisb - Auto Tool Sales :
Date: June 21, 2014 @ 2:29 pm
Could be leaves blocking the flow. I’d pull the blower and see if there’s excessive leaves or other debris. Good Luck.
Brad :
Date: June 25, 2014 @ 8:52 pm
Hello, I have a 06 ram 2500 5.9 with 509,000 miles, where would the vacuum line be located? Air is just blowing out the defrost, also where is the most common place that the a/c leaks from in these trucks?
dennisb - Auto Tool Sales :
Date: June 26, 2014 @ 8:14 am
Mostly older systems (2001 and older) use vacuum operated control motors to open and close the evaporator case doors and most newer systems (2002 & up) use electric motors that do not require vacuum. On systems that are vacuum operated, the vacuum line usually goes through the firewall near the heater hoses. It runs from the vacuum cannister to under the hood or behind the bumper cover to the evaporator case and AC control head.
The most common Freon leak is the evaporator on all Chrysler products, however anything can leak that the refrigerant passes through. Compressor, hoses, condenser, switches etc. That’s why it’s best to use a good refrigerant leak detector (tester) to pinpoint refrigerant leaks. Car air conditioning UV dye is also another method for finding leaks. Good Luck
mike :
Date: June 28, 2014 @ 2:48 pm
I have a 2003 dodge durango that the rear ac blows cold but the front blows hot… Any ideas…
Thanks
dennisb - Auto Tool Sales :
Date: June 28, 2014 @ 2:59 pm
Most likely a front expansion valve…
Darren :
Date: July 1, 2014 @ 11:48 am
Dennis,
I have a 2003 Ram 1500. When I turn on the a/c the truck starts missing and when I am at idle it gets worse. what do you think causes this? If I run the a/c for over 10 min the truck starts to overheat.
dennisb - Auto Tool Sales :
Date: July 1, 2014 @ 12:53 pm
Darren, this is an engine running or drivability issue and an overheat issue not an AC problem. See our articles on misfires and idle and overheating. But I’d pressure test the cooling system and maybe do a carbon test to make sure there’s no exhaust in the cooling system and go from there. Check to see if there’s any codes stored… Good Luck.
larry :
Date: July 8, 2014 @ 10:34 pm
2001 dodge ram 2500. replaced Ac fan. now it is not blowing hard at all. door is working when we take off glove compartment. I am stumped
dennisb - Auto Tool Sales :
Date: July 8, 2014 @ 10:51 pm
Larry, I once installed a new blower motor and the wires were reversed. It sounded fine but it obviously didn’t blow properly. If it’s not turning fast could just be a defect. I’d make sure it turns easily by hand also. Good Luck.
Vick :
Date: July 9, 2014 @ 12:13 am
Hey Dennis I have 2006 ram 1500 just replace the compressor and the fan but on driver side blow cold and passenger blows warm And I have it on high volume and then I have low airflow but I hear the fan blower blowing hard any idea
dennisb - Auto Tool Sales :
Date: July 9, 2014 @ 6:47 am
Vick, a huge difference in side to side temp can be from low refrigerant. A little variance is normal. If it’s a dual zone system, there could be a door issue, but first I’d make sure the charge is correct. See our AC gauge readings explained for help reading the gauges. As far as the air flow volume being low, it’s possible that the wires are reversed on the blower motor since you just installed it. Especially if the airflow was good before the old blower failed. I once installed a new blower motor and the wires were reversed. It sounded fine but it obviously didn’t blow properly. You already know about the possibility of a door issue since you read this article. Good Luck.
JD :
Date: July 9, 2014 @ 8:20 am
2001 Dodge Ram 1500 5.2l – Just purchased. AC is *always* on but NO heat. Temp control does nothing when turned from blue to red. All blend doors work fine. Fan switch works in all positions. Where to begin?
Great blog – Thanks!
dennisb - Auto Tool Sales :
Date: July 9, 2014 @ 8:33 am
I don’t see how the blend door could be functioning properly as you said “All blend doors work fine“. The blend door (or doors, plural if it’s a dual zone system) makes the air entering the case blow across the heater core fins instead of the evaporator core. If the door or doors were moving properly you’d feel the difference. I’d think that this is not occurring due to the actuator or the control head etc., being faulty.
JD :
Date: July 9, 2014 @ 9:05 am
WOW -great response time – Thanks & Good Morning. “blend” doors vs. the control that directs air flow to dash, defrost, floor, combo – all those work. My error – the terminology of “doors”. Fortunately, this is one of the RAM 1500’s with a VERY deteriorated dash. I can just pick away the pieces and get in there to see.