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hey guys just wondering before i take my truck in for the end of its 3yr bumper warranty. when i switch between heat and cool the airflow decreases significantly, it still warms the truck but i'm wondering if thats normal?
 

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I crack my window just a bit to let the cool air out quicker

If that doesn't work on yours, maybe you didn't get the climate control software update yet
 

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there is no problem with the heating, say you turn the blower on high/ cool then turn the blend knob to hot, the amount of airflow drops. i never noticed it till recently just wondering if thats normal
 

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I dont know if its normal in automotive but fan speed is meant to be slower on heat than on cool to allow the air to heat up as it goes through the heat exchanger. Thats how it works in residential and commercial HVAC.
 

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hey guys just wondering before i take my truck in for the end of its 3yr bumper warranty. when i switch between heat and cool the airflow decreases significantly, it still warms the truck but i'm wondering if thats normal?
I don't know if it's normal but I noticed it in mine as well. I was going to ask the dealer the next time I was in.

f that doesn't work on yours, maybe you didn't get the climate control software update yet
What is this update you speak of kemosabe?
 

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If i were to assume that cool air comes from outside and bypasses the heatercore and the a/c isn't on then when the heat IS on, the resistance from air passing through the heater core is what is causing the less air flow condition that you speak of.

Watson, you may light my pipe now...
 

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Discussion Starter · #7 ·
If i were to assume that cool air comes from outside and bypasses the heatercore and the a/c isn't on then when the heat IS on, the resistance from air passing through the heater core is what is causing the less air flow condition that you speak of.
the cold air may bypass the heater core but instead it travells through the evaporator core. that may not be it but i'm getting the impression its normal. maybe they made the heatercore passage smaller so you wouldn't burn your face with a high volume of 200 degree air.

Watson, you may light my pipe now...
yes you may:smileup:
 

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Hemilancer, I notice the same reduced airflow when I switch from hot to cold while maintaining the same fan speed. I had my vehicle checked out and the dealership stated it was normal. There was no talk of an updated software though. I might go back and ask about this upgrade.
 

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It is my understanding that the 2009 - 2011 Rams no longer have cabin air filters. In one aspect, that can lead to a dirty interior. On the other hand, it's good because it allows the air to move freely. If you remove your lower glovebox, you will see the fan motor housing. Above it is the automated vent that switches between the outside air and interior recirculation air. If you place your hand on the top of the fan motor housing unit, you will feel a grate. This is the air entrance to the previous air filter cavity that has been sealed (but they left the "T" box face to be cut out so you can install an air filter on your own). Below this air chamber is the fan it self, and man, it's lacking in size and power. Now that I've described a picture, I'll do my best to answer your question based on my "i'm bored and lets take something apart..." experience / observations. The airflow is redirected when it has to go through the heater core. Airflow loses it's speed the more obstacles it encounters. I love my Dodge Ram (bought my first truck last Feb), but yesterday I was determined to find out why I had no airflow to the rear center air vents in my crew cab and that is when I discovered, 1. no air filter, 2. a week fan, 3. a small fan, & 4. the rear center air vents are connected to the front center air vent chambers. I have to close the front center air vents so my little girl (who sits in the back middle) doesn't freeze in the winter and burn in the summer. Do I want an interior air filter? ABSOLUTELY - but only after a better blower is installed that can handle the restriction of an air filter. This explained the mystery of why the rear floor vents worked great but the rear center vents had restricted airflow. The dealership swore it was working fine and after pulling parts and climbing around with a flashlight, I discovered it is working correctly based on the design. This design needs a better blower.

I did find it pretty neat that you can install your own air filter pretty cheap.

I hope my unofficial answer based on my official curiosity helps. I hope someone else has a better answer or can supplement this.
 

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I too have been into the fan and ductwork on my 09 QC hemi and installed the filter while I was there.Your right micar71, the fan is under powered compared to some GM trucks I've owned. But I didnt really notice any difference in flow after installing the filter.If you want higher fan speed you gotta put it on high on these trucks. They all seem to do it.
 

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K17 recall, mine was not one of the vehicles involved, but they checked it out anyway & did a software update

2009-2010 K17 Recall

--------------------------------------------------------------------------------
2009-2010 (DS) Ram Truck (1500 series)
2010 (DJ) Ram Truck (2500 series)
2010 (D2) Ram Truck (3500 series)



NOTE: This recall applies only to the above vehicles built through May 22, 2010


(MDH 052220)

.


The HVAC mode door actuator gears on about 225,000 of the above vehicles may
break and result in the inability to fully control the HVAC functions.
All involved vehicles must have updated HVAC control head software installed
and the mode door actuators must be tested and replaced as required.
 
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