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Air Conditioning Ice Blockage

7185 Views 11 Replies 7 Participants Last post by  Chilled Man
It's finally gotten hot here again but I've noticed an issue.

When i run the AC for a while, maybe 1 hour, it stops blowing. Very specifically:

- The condenser still works, there's a trickle of VERY cold air coming from the vent.

- The blower still works, it whirs when you push it up to hi (or run it on auto) and it responds normally when you turn it down. When it's full blast the trickle of air coming out of the vents is higher than when its low, but it's GREATLY reduced from normal operation.

- Whether it's on Auto or a specific airflow setting it doesn't make a difference.

- If i turn it off for about 30 minutes, it works fine when I turn it back on.

Seems to me like there's some icing going on that's blocking the airflow.

Anybody have any experience with this?
1 - 12 of 12 Posts
Re: Air Conditioning Ice Blockage (LoveMyS60)

Condensate drains might be partially plugged.
Re: Air Conditioning Ice Blockage (LoveMyS60)

Have you checked your condensate drain, if parked with ac on do you get a water puddle on the ground. If the drain is working correctly than it could be low pressure cutout switch bad or out of adjustment, low freon charge, or faulty orifice valve.
I think its the low pressure cutout. After air temp inside car cools down check to see if ac compressor is cycling on off as it should. Good news is low pressure cutout switch can be replaced without loosing freon.
4
well we got some partial right info here


Low Pressure cut off turns on due to low refigerent.

You get low refigerent due to a leak.

So ....

You have a leak , fix the leak , refill the system and your golden


Hopefully its your condensor on the outside of the car and rock poped a hole in it .

And not your evap.............. that = $$$$$$

12+ in HVAC


This is what your Evap looks like


Not your actual evap just a pic of a frozen evap.
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Have the same problem with my S60
Can't seem to find what it is either
Re: (Chilled Man)

Low pressure cutoff also cycles compressor under normal conditions to prevent icing and save fuel. Without low pressure cutout evaporator would ice when fan speed is low.
I have a motor vehicle air conditioning technician certification.
Re: (vlvman)

Please se this link;
http://autoacrepairs.com/actheory.html
Under CYCLING CLUTCH/ORIFICE TUBE SYSTEM
Re: (vlvman)

This happened with my '04 v70. It smelled awful after two years and then started to ice up (ac condenser coils). I took it in and they filled the ventilation system up with a mildewcide and odor masking agent that smelled worse. Ultimately, they ended up replacing the evaporator, particulate filter and a sensor(30665118-3), and activating the afterblow. I have not had a problem since.

The way to tell if you have an icing problem is the ac will work initially, but the longer you drive, the less air you will get--even though the fan is blowing. It will also recover overnight (the ice melts) and then do the same thing again next time the ac is used, especially so if it is very humid out.

It is best to get on an odor problem fast. Mildew is difficult if not impossible to get rid of once it is established.
Re: Air Conditioning Ice Blockage (LoveMyS60)

Quote, originally posted by LoveMyS60 »
It's finally gotten hot here again but I've noticed an issue.

When i run the AC for a while, maybe 1 hour, it stops blowing. Very specifically:

- The condenser still works, there's a trickle of VERY cold air coming from the vent.

- The blower still works, it whirs when you push it up to hi (or run it on auto) and it responds normally when you turn it down. When it's full blast the trickle of air coming out of the vents is higher than when its low, but it's GREATLY reduced from normal operation.

- Whether it's on Auto or a specific airflow setting it doesn't make a difference.

- If i turn it off for about 30 minutes, it works fine when I turn it back on.

Seems to me like there's some icing going on that's blocking the airflow.

Anybody have any experience with this?

Have your car scanned with VIDA and have the tech check the Evap Temp Sensor reading. They have an issue of reporting much colder than they are and they shut off the compressor. Too low of pressure on the low side will do this as well, and I've yet to see a frozen evaporator on a Volvo. I've made them "throw snow" but not completely freeze in any short time.

Another plague with Volvo's AC system is the Compressor Clutch. Will give the exact same symptoms as you state. Basically once the clutch gets hot, it disengages due to an open in the clutch coil windings. Once its off, it cools down and will work again for another few minuted before shutting down again. It usually gets worse until it just doesn't work anymore.
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Re: Air Conditioning Ice Blockage (Oceans60R)

Oceans: thanks for the explanation. I always thought it was icing, and my dealer never explained otherwise.

Before it was fixed, my a/c seemed to be ok up to about 90F and moderate humidity. It only acted up when the humidity was very high and occurred on trips longer than 45 minutes.

Since they replaced the sensor and the evaporator (presumably for the odor) it has been working fine.

I experienced the overnight recovery, could that have been sensor related, too, or just the compressor, and is that a sign my compressor had problem that was never addressed?
Re: Air Conditioning Ice Blockage (MrTippy)

I suspect the compressor clutch is the culprit here. I don't recommend just replacing the clutch as they are usually seized to the compressor shaft and it just waists time and effort to remove and then shimming and such. Some do it yourselfers might try it but most people don't have the special tools to remove the clutch from the compressor nor do they have AC recovery and charging equipment.

If its found to be the clutch, I would replace the compressor as it comes with a new clutch.

What I used to do to determine if the clutch was indeed the culprit was to fashion a length of wire with a light bulb in it. I would then back probe the compressor clutch signal wire down near the compressor and put the bulb end up near the wiper blades and drive the vehicle. Don't forget to ground the other end. Now drive the vehicle until the AC stops working and note if the bulb monitoring the compressor clutch signal is still lit. If the AC stops blowing cold and the light is still on, pop the hood and use a flashlight to see if the compressor is not turning. If its not turning but the light is on, then its a bad clutch guaranteed. Now if the AC stops cooling AND the light goes out, then it is something else in the system. Could even be an ambient temp sensor. I've seen them when bad default to -40C and will prevent the compressor from coming on. However the light test will clue you in to what is happening as there will either be a signal from the CCM or not. Further tests may be necessary but start with the basics and usual suspects.

http://********************/smile/emthup.gif
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I agree with Ocean also on this the Compressor clutch on all volvos seems to be a huge issue.

between that the evap and then condensor makes the AC system a total PIA .

Major reason why I got rid of mine
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