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A/C Cold then Hot?

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Old Aug 15, 2009 | 05:42 AM
  #1  
wutagoalie's Avatar
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Default A/C Cold then Hot?

Hey guys, 2002 1.7L.

I have this issue with my A/C, when i first get into the car my first 10 minutes of driving the A/C works great,(nice and cold) Then after about 10 min it starts to blow out warm air? If i shut the air off and drive for 10 or 15 more minutes, the cold will come back on but only for a short period of time.

What is this? and what is the fix?

Thanks
 
Old Aug 15, 2009 | 07:07 AM
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It could be a few different things. Drive until it stops cooling then pull over (leave the engine running and the A/C button pressed) and check under the hood--

Is the condenser fan running?
Is the compressor engaged?
Is the pipeline from the firewall to the compressor cold, or warm?
 
Old Aug 15, 2009 | 07:37 AM
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If refrigerant pressures are fine in the system, then check the A/C thermostat in the evaporator and the pressure switch near the receiver/dryer.
 
Old Aug 15, 2009 | 09:43 AM
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Thanks guys, where is the condenser fan located?
 
Old Aug 15, 2009 | 11:38 AM
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It's right behind the radiator. Technically the fan on the left side of the car is the condenser fan and the one on the right side is the radiator fan. But the 2002 has a full-width condenser, so both fans should run with the A/C on. The condenser is the radiator-like unit that rejects heat from the A/C system. It is mounted in front of the radiator to get it the coolest air possible.
 
Old Aug 15, 2009 | 06:54 PM
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I had the exact problem on my 2002 civic just this week. Checked everything electrical and finally I wired in a test lamp to the compressor clutch visible while driving and found the clutch had power when the ac quit. Also I visible saw the clutch disengaged with the light on. Bought a used compressor with a clutch on e-bay. Find out next week if I'm right.
 
Old Aug 16, 2009 | 06:34 AM
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If you have power to the clutch but it doesn't engage, no need to replace the whole compressor. Usually you can just reduce the clutch gap. Take the shaft nut off and remove the clutch plate. There are some very thin shim washers on the shaft; remove some of them and put the plate back on. Check that the clutch does not drag when off. This can all be done while the system remains charged with refrigerant.
 
Old Aug 17, 2009 | 05:09 AM
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I checked out the fan situation, i pulled over when the a/c started to blow warm air, and yes both fans near the Rad were running with the A/C button on. When i press the A/C button to turn it off, both fans near the rad also turn off.

What would be the next step, to check for?

Thanks
 
Old Aug 17, 2009 | 05:26 PM
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I wasn't going to replace the compressor, it just happened to be cheaper to buy the whole thing. Thanks
 
Old Aug 18, 2009 | 04:41 AM
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I checked out the fan situation, i pulled over when the a/c started to blow warm air, and yes both fans near the Rad were running with the A/C button on. When i press the A/C button to turn it off, both fans near the rad also turn off.

What would be the next step, to check for?

Thanks
 



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