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Discussion Starter #1
Hi all;
Lately the manual air conditioning in in my 2002 GLS variant has been properly blowing cold air, and sometimes it blows outside temp air.
it just seems to be working normally and then the cold air stops and it blows
warm air, then if i'm lucky the cold will start.
Any ideas on what to check?
Thank you in advance!

Curtis
 

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Sounds like you may be over pressurized or under pressurized. I added in some 134A in hopes of getting mine a tad colder, but mine started cycling like your describing. Removed a few pounds and it runs great now.
 

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Discussion Starter #3
1 badWGN
Thank you for the response. I'll check into it :thumbup:
Anyone else have any ideas?
Thanks,
Curtis
 

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Discussion Starter #4
Bump with further information.
I tested the referigerant today. When it's blowing cold air the reading is 35
When it's blowing ambiant air the pressure is like 150
Does this clue help with any diagonsis you may make?
Curtis
 

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Looking back at your original post and then your others, it may be a little difficult to try to analize this here.

A couple of indications: You are getting 35 degrees. Does it start blowing ambient when it reaches 35 or just any old time? If any old time, maybe compressor clutch or metering valve. If at 35, then you may have high pressure switch problem. And your other obvious things like under or over pressurized, leaks etc., but I doubt it. In any case, you may want to go to the stealership because you should still be under warranty and them deal with the hassle.
 

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Discussion Starter #7
1 bad:
Thanks again for the response.
I was unclear in my previous post.
The 35 I referred to was not the temp but the (PSI) pressure reading of the refrigerant at the low side tube connection.
The 150 was the pressure of the 134A whren the fan clutch was not running.
I'm out of warranty with 78,000 miles on my 2002 (yeah, I drive alot) , but this car is sooooo nice to ride in all day long!
Curtis
 

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The thing I don't understand is why you are running your A/C in March. Just how hot is it there?

Put a thermometer in your vent: How cold is the A/C blowing when it is working? How cold is the A/C blowing when it is "not working"?

In any case, the A/C pressure switch may be faulty. Or (cringe) the condensor may be blocked.
 

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I was unclear in my previous post.
Might have been me as well, I WAS TIRED!

35 on the low side vs 150 on the high side seems kind of steep to me. What was your pressure when the clutch engaged? That's what pressure we would need to see.
 

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Discussion Starter #10
OakHillVariant;

I don't know about the weather there in beautiful Texas, but here in LA LA Land it's been in the 90's lately. Today the mercury hit 97. Definately hot enough to want the A/C!
Please tell me more about the A/C pressure switch. Is is easy to get to? Can I change it myself?
Have you done it?
Thanks in advance.

1BadWGN:
When the compressor is running, the pressure is 35. When the compressor is not running the pressure is about 150.
Thanks for your help
Curtis
 

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Okay. Low side is 35 when compressor was running. How about the high side?

To change that switch, you have to evacuate the system to change it out. Change it out, then suck it back down to a vacuum and fill her back up with 134A. Normal A/C procedures. But if you don't have the equipment or know someone who does, $$$ for a shop to do it. Impex is selling the switch for $155.00 (Part Number: 8D0959482B: Double Check This!!!). I 'm not certain on how to check to see if your pressure switch is good.

 

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OakHillVariant said:
The thing I don't understand is why you are running your A/C in March. Just how hot is it there?

Put a thermometer in your vent: How cold is the A/C blowing when it is working? How cold is the A/C blowing when it is "not working"?

In any case, the A/C pressure switch may be faulty. Or (cringe) the condensor may be blocked.
Today my car's temp gauge registered 97 :crazy: It is 72 right now. :cry:
 

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The first thing you should do is rule out low refrigerant.
Checking just the low side pressure isn't going to tell
you the whole story. You need to check
the high side pressure.

Procedure:
(while car is off).
Disconnect the electrical connector from the cooling
fan in the engine compartment
Hook up a test gauge to the high side A/C line.
Start car.
Turn on the A/C switch.
turn your blower to high
turn the heat full on.
Direct air to floor.
run the engine up to about 1500 RPM.
(you'll need a helper maybe).
Check pressure gauge.

Pressure should go up to about 230PSI within 30 seconds.
If it doesn't get that high (and the compressor is indeed
engaged), then you need to add refrigerant.

Note: A/C system high side pressures can vary with
outside temperature. You may see pressures as high
as 290 PSI. If you see something over 290PSI, then
you need to evacuate some refrigerant.

Don't forget to reconnect your fan!

If the compressor doesn't engage with the above procedure,
then more digging is involved. If it were me, at this point
I would call in a professional.
 

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Discussion Starter #15
Thank You All very much! :bow:
I believe i'll let a pro have a whack at it.
Curtis
 
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