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A/C Inconsistent - Cold(Normal) for 10 sec no Icy air for 3-5 sec


VEF8's Avatar
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11-01-04, 06:57 PM   #1  
VEF8
A/C Inconsistent - Cold(Normal) for 10 sec no Icy air for 3-5 sec

My car has this problem:

The A/C air coming out from the vent was cold for 10 sec / not icy air for 3-5 sec.

At the lowest temperature the air wasn't much colder than 23*C.

What could be wrong? Compressor?

 
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11-02-04, 05:05 AM   #2  
not enough info...

...depending on what kind of vehicle you have may determine the correct procedure to follow. you need to take it to a competent HVAC tech and have it performance tested...where operating pressures and outlet air temp are measured against ambient temp and humidity level. with the limited info you give it could be a refrigeration or an air delivery issue...or i guess...nothing at all.

 
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11-08-04, 10:05 PM   #3  
VEF8
hi carguyinva,

Thanks for your information. My car is less than a year old and thus still under warranty. So I bought the car back to the sole distributor for a check up.

And the service adviser told me the problem was due to my air in take mode being set to fresh air instead of recirculation.They added, as it is taking fresh warm air outside, the system couldn't cool the air in time, which explains the interval without cold air. And I wasn't allowed to stick around when they do
the servicing.

But it still gave me the same problem,by setting the mode to recirculation, just make fan speed a bit stronger but didn't rectified my problem.

But I found out that if I set the temperature 1*C lower, the cold air flow will be contstant.

I pretty sure there's something wrong with the A/C, if not why do I need to set the temperature 1*c lower to get the same sort of coolness.

Could it be the thermostat?


Last edited by VEF8; 11-08-04 at 10:20 PM.
 
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11-09-04, 04:13 AM   #4  
most systems now...

...use some kind of compressor cycling strategy to help control evap temp...the other benefit to cycling the compressor is that it improves fuel economy a little. when the compressor cycles, the outlet air temp will go up some...how much depends on the ambient air temp and at what low side pressure the closes the switch and turns the compressor back on. changing the requested air temp will obviously affect cycling times on an electronic OR automatic system. this is why I say that nothing may be wrong with it...without watching it operate and feeling the described temp change, verifying it with a thermometer and comparing that data to prescribed operating parameters, it's impossible to tell whether you have a bonified performance issue or not. my advice is to demonstrate exactly what you perceive as the issue to the technician...not the service advisor, but the tech who will check it out and ask him to do the performance test according to the manufacturer's procedure AND record the data for you. this should either show that there is a real problem...or put your mind to rest that there isn't and that what is happening is a performance characteristic and something that you need to adjust to.

ps...i'm not buying that the air doesn't have time to get cooled...yes...outlet air temp goes up a little when cooling warmer outside air...but if it wasn't made to work that way, that operating option wouldn't still be there after all these years. recirc is for cooling down an extremely warm car (sitting in the sun)...using outside airis for maintaining a comfortable interior temp and maintaining a constant fresh air supply

 
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11-09-04, 05:55 PM   #5  
VEF8
Thanks for the useful information. I'll present my case to the technician.

Another thing, is there such a thing as setting the temperauture at certain
temperature say 23*C will put the air con on auto mode, regradless whether
auto option was selection, and the air con compressor will cut in and cut by itself?

I've heard something to that effect for home air con and the temperature mentioned is from 22*C to 23*C.

Someone also mention that the servo motor could also be the problem for my case. How does the servo motor actually regulate the temperature?

Thanks again.

 
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