Hi,When I switch the air to blow at the 'feet' only, why can't I get internal circulating air? Also, sometimes, when I push the button for internal air, the A/C comes on too, why is that? Thanks.

Good question! I've wondered the same thing!

I wonder that for a while myself. it is the same situation like how your AC will turn on when you switch the air outlet from bottom to top.

I believe the idea is when you have the heat on, the air should be coming out from the bottom outlet (hot air rises) to warm up the interior faster, and for some reason the internal circulating air function is disabled. if you have driven a car with auto climate control, you will notice when the temp desired is at say 80F, the climate control will automatically change the air outlet to your feet area.

When you switch it to cold air, you can then choose to enable to disable internal circulating. it is recommanded when you have your AC on, you should keep the cold air circulate (stay cool and save on gas). If I remember correctly, when you turn the switch to "MAX/AC, the AC and internal circulation will automatically turn on.

with that said, and if my guess above is correct, shall we call it nissan's semi-auto climate control???

My wife's 06 Altima 2.5s does the same thing.

It's almost the same for '03 Altima. Recirc mode only works if the upper vents are selected. In defrost or foot vent mode, you cannot select recirc mode.

On the same topic...

Service Bulletin NTB03-048a covers the new A/C operation on '03 and newer Nissans. Note: some of the newer models are not listed, but I believe the operaton is the same.

Quote »

NTB03-048a

A/C COMPRESSOR OPERATION DIFFERENTFROM EARLIER MODELSThis bulletin has been amended. The Applied Models have been updated. No other content hasbeen changed. Please discard all previous versions of this bulletin.APPLIED VEHICLES: 2003 – 2006 Sentra (B15) – with manual A/C2003 – 2004 Altima (L31) - with manual A/C2003 – 2004 Frontier (D22) - with manual A/C2003 – 2004 Xterra (WD22) - with manual A/C

SERVICE INFORMATIONVehicle owners may report the A/C does not turn OFF at times.Even though the A/C switch is OFF:• The A/C compressor cycles.• There is slight idle speed fluctuation.• The outlet air temperature is cool.

The above conditions may be normal.

There have been HVAC system improvements and design changes.• These changes affect the way the A/C compressor operates.• These improvements help reduce window fogging by dehumidifying the air.

Nissan Bulletins are intended for use by qualified technicians, not 'do-it-yourselfers'. Qualified technicians areproperly trained individuals who have the equipment, tools, safety instruction, and know-how to do a jobproperly and safely. NOTE: If you believe that a described condition may apply to a particular vehicle, DONOT assume that it does. See your Nissan dealer to determine if this applies to your vehicle.

For the Applied Vehicles in this bulletin:• When a defrost mode is selected (either “defrost” or “foot/defrost”),and• the outside temperature is more than 36 – 37°F (2 - 3°C),• the A/C will remain ON with the Mode Control Knob in any mode position, evenif the A/C button is OFF.NOTE: The A/C indicator light will not be ON, when the system is operating asdescribed above.[/quote]Courtesy: Nissan Motor Corp.

You can add one more detail:

Once you select defrost mode, the only way to deactvate the A/C is:

1 - Select another mode besides defrost or defrost/heating.2 - Be sure the car is stopped and in park, then completely turn OFF the car.3 - Restart the car.

Obviously this new operation was added as a safety feature.


Modified by philipa_240sx at 9:59 AM 2/25/2008

Has anybody else noticed that the center dash vents have a lot less output than the ones near the doors?

You're probably right. Semi-automatic cc sounds good to me. Our last two cars have had auto climate control and it sucks. I know exactly where I want the temp and it hardly ever is what the auto cc decides it should be! The problem is that to get other features I really wanted, the package deal always included auto cc.

An update from my post above:

With the Rogue you now have the option to defeat the A/C once you deselect defrost mode. Before, you actually had to turn the car off!