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Discussion Starter #1
I noticed from time to time when i accelerate ventilation fans tend to drop speed. Not sure if the a/c shuts off for a brief moment as you can feel warmer air exit the vents. Nothing of concern to me as the a/c works fine, just wondering if it does this for a reason. Knowing the ac is a huge power consumption to the vehicle, im wondering if it does this for the engine to put more power where needed.

on another note
i did a test on the HWY this past Saturday omw to a wedding coverage. 2hr drive there i used the a/c with seat vents on and got about 22/23mpg. On the way back i did the opposite and got 29.2mph, not too shabby :smile:
 

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Out of curiosity, what was the fan speed at when you were running the AC, was it high or did you have it moderately low?


I have not noticed what you have described but I know that with my AC on and the fan speed low, even though it does blow in cold air, I can still feel a bit of warm/hot air coming through the vents.
 

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Discussion Starter #3
Out of curiosity, what was the fan speed at when you were running the AC, was it high or did you have it moderately low?


I have not noticed what you have described but I know that with my AC on and the fan speed low, even though it does blow in cold air, I can still feel a bit of warm/hot air coming through the vents.
your right, its was higher then 3 bars
 

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Sorry I can't confirm with you whether or not this actually happens, but I can tell you this is an intended design feature in many vehicles made in the last 15-20 years. You will accelerate faster with the AC off, so the computer is programmed to do this in many cases.
 

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Sorry I can't confirm with you whether or not this actually happens, but I can tell you this is an intended design feature in many vehicles made in the last 15-20 years. You will accelerate faster with the AC off, so the computer is programmed to do this in many cases.
This makes a lot of sense

Did you have ECO mode turned on? If so, it will reduce the power of the HVAC system to save on fuel.
No ECO.. I tried it with fan at full blast with no a/c and it doesn't do it making it tied to power needed at acceleration.. I think mwl001 is correct..
Just wondering, not an issue, my 05 odyssey didn't do this nor the Hondas prior to the odyssey.
 

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Ive noticed an inconsistency in my AC as well while accelerating. It doesnt seem like the compressor is cutting off but more like the blower level drops when i have it up high. I noticed it periodically on my 15 optima also so Im guessing its normal.
 

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On my Accent it is most noticeable when you lift the throttle. The AC will kick out every time for 5 seconds. Never go WOT to see if it cuts out then.

What I do is add a hot wired LED to the AC relay coil ground. Then when the ECU turns on the relay for the clutch, the LED is on.
 

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I can understand the compressor being cycled off under hard to WOT acceleration, but nothing is really gained by a reduction in the blower motor speed. Yes, you decrease the alternator load a bit but the biggest bang for the buck would be by cutting the compressor off. That would of course cause warmer and more humid air to be put out until the compressor is engaged again.

There could also be a short timer that would keep the compressor off after such an event to allow the refrigerant pressures to stabilize a bit before the compressor cycles back on.
 

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I can understand the compressor being cycled off under hard to WOT acceleration, but nothing is really gained by a reduction in the blower motor speed. Yes, you decrease the alternator load a bit but the biggest bang for the buck would be by cutting the compressor off. That would of course cause warmer and more humid air to be put out until the compressor is engaged again.

There could also be a short timer that would keep the compressor off after such an event to allow the refrigerant pressures to stabilize a bit before the compressor cycles back on.
I'm guessing the reduction in blower speed is a courtesy; much like when the vehicle starts, the blower speed doesn't ramp up until the temperature matches what is desired. If the system will be blowing hot air, you don't want it in the vehicle if you're running AC.
 

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The lower blower speed would reduce the outside air being brought in and not cooled. Or if in recirculate it would slow down saturating the evaporator with heat.
 

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I have noticed the ac turned off after a hard acceleration hand has failed to turn back on. I assume there is a sticking relay
 
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