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AC is fully charged but not blowing cold air??

Posted: Wed Apr 20, 2022 7:45 pm
by mcdavidhome
This problem has me stumped. Ac is fully charged but not getting cold air out the vents only warm air. What could be some common reasons for this problem?
Update: So the problem was exactly what most of you stated that it wasn't fully charged with enough freon. I purchased a set of manifold gauges as suggested and learned the charge ranges. Thanks for all the help. It was greatly appreciated.

Re: AC is fully charged but not blowing cold air??

Posted: Wed Apr 20, 2022 8:13 pm
by 95naSTA
How do you know it's fully charged? If you have a set of gauges does the low side drop with the a/c on and high side increase?

Take a look at the a/c clutch with the engine running and see if it's engaged with the a/c turned on inside. If you're not sure turn the a/c off and see if there's a difference.

If the clutch is engaging, your compressor is worn out. If it's not, it could be one of the pressure switches.

Re: AC is fully charged but not blowing cold air??

Posted: Thu Apr 21, 2022 10:24 am
by harofreak00
Manual calls for 2.2lbs (35oz), but the system performs so much better with 2.5lbs (40oz).





....oh to live in a place that needs AC already (looks at current outside temp of 35°F)

Re: AC is fully charged but not blowing cold air??

Posted: Thu Apr 21, 2022 6:04 pm
by Evan0801
The blend door might be worth looking at too.

Re: AC is fully charged but not blowing cold air??

Posted: Thu Apr 21, 2022 7:42 pm
by 95naSTA
^^ Good point

Re: AC is fully charged but not blowing cold air??

Posted: Sat Apr 23, 2022 9:03 am
by nos4blood70
harofreak00 wrote:Manual calls for 2.2lbs (35oz), but the system performs so much better with 2.5lbs (40oz).





....oh to live in a place that needs AC already (looks at current outside temp of 35°F)
I had mine running at 2.2 for years and it was fine for most cases. Recently replaced my compressor and added the 2.5 per Andrew's advice and dangggggggg lol Not only does it produce colder air but it also does it faster.

Re: AC is fully charged but not blowing cold air??

Posted: Tue May 03, 2022 10:31 am
by mcdavidhome
95naSTA wrote:How do you know it's fully charged? If you have a set of gauges does the low side drop with the a/c on and high side increase?

Take a look at the a/c clutch with the engine running and see if it's engaged with the a/c turned on inside. If you're not sure turn the a/c off and see if there's a difference.

If the clutch is engaging, your compressor is worn out. If it's not, it could be one of the pressure switches.
My gauges show that is has sufficient freon in the system and the AC clutch is engaged and the low side line is moderately cold.

If it is a issue with one of the pressure switches where are they located?

Re: AC is fully charged but not blowing cold air??

Posted: Tue May 03, 2022 10:34 am
by mcdavidhome
Evan0801 wrote:The blend door might be worth looking at too.
I heard a few people tell me about the blend door, but trying to find the blend door location and replacement procedures thru google searches has turned up nothing for me.

Re: AC is fully charged but not blowing cold air??

Posted: Tue May 03, 2022 10:59 am
by mcdavidhome
mcdavidhome wrote:
95naSTA wrote:How do you know it's fully charged? If you have a set of gauges does the low side drop with the a/c on and high side increase?

Take a look at the a/c clutch with the engine running and see if it's engaged with the a/c turned on inside. If you're not sure turn the a/c off and see if there's a difference.

If the clutch is engaging, your compressor is worn out. If it's not, it could be one of the pressure switches.
My gauges show that is has sufficient freon in the system and the AC clutch is engaged and the low side line is moderately cold.

If it is a issue with one of the pressure switches where are they located?
https://imgur.com/SyP7fwa

Re: AC is fully charged but not blowing cold air??

Posted: Tue May 03, 2022 11:56 am
by mcdavidhome
Evan0801 wrote:The blend door might be worth looking at too.
Thanks

Re: AC is fully charged but not blowing cold air??

Posted: Wed May 04, 2022 11:39 am
by harofreak00
What were your gauges showing and what was the ambient temp and humidity?

I promise you its just low freon. Spend $5 at Walmart and put a 12oz can in, you'll be happy you did.

Re: AC is fully charged but not blowing cold air??

Posted: Sun May 08, 2022 7:23 pm
by mcdavidhome
harofreak00 wrote:What were your gauges showing and what was the ambient temp and humidity?

I promise you its just low freon. Spend $5 at Walmart and put a 12oz can in, you'll be happy you did.
The temp was 87 degrees with 47% humidity.
Here's the a pic of the gauges.
https://imgur.com/a/Pyb355N
I had already added a can of freon. I did notice that the compressor makes kinda a winding noise when it's engaged.

Re: AC is fully charged but not blowing cold air??

Posted: Mon May 09, 2022 10:52 am
by harofreak00
Sorry, but that silly little gauge isn't telling you anything, I was assuming you were using proper gauges. You need to know high and low sides, and even then it doesn't tell you how much freon is in the system, just the pressures.

Image

I just did an AC job on Friday and there was no change in pressures between 25-35oz. I use a digital scale on my freon tank to determine how much is added to the system.

Image

My advice, get your system evacuated by a professional, and then ask them to charge it to 40oz exactly. They will be able to tell you exactly how much is evacuated.

Re: AC is fully charged but not blowing cold air??

Posted: Mon May 09, 2022 3:46 pm
by mcdavidhome
harofreak00 wrote:Sorry, but that silly little gauge isn't telling you anything, I was assuming you were using proper gauges. You need to know high and low sides, and even then it doesn't tell you how much freon is in the system, just the pressures.

Image

I just did an AC job on Friday and there was no change in pressures between 25-35oz. I use a digital scale on my freon tank to determine how much is added to the system.

Image

My advice, get your system evacuated by a professional, and then ask them to charge it to 40oz exactly. They will be able to tell you exactly how much is evacuated.
My apologies I am a bit of a novice when it comes to Automotive AC but I will take your advice and take it to a professional and have it diagnosed.
Also I will go ahead and purchase the proper gauges that you advised so I can learn how to use them in the future. Thanks for all your help!

Re: AC is fully charged but not blowing cold air??

Posted: Sat Jul 09, 2022 3:12 pm
by 2000SE
Replaced the compressor, orifice tube & receiver dryer after flushing the system.

Original compressor worked well at 50/240psi.

New compressor needs 55/245psi to blow as cold.

Does a new compressor have a break-in period?

What is the psi that the relief valve on the compressor opens?

BTW, using an environmentally friendly charge with the orginal compressor, discharge air on the passenger side in the summer read as low as 12 F.

Re: AC is fully charged but not blowing cold air??

Posted: Thu Sep 08, 2022 3:29 pm
by mcdavidhome
mcdavidhome wrote:
harofreak00 wrote:What were your gauges showing and what was the ambient temp and humidity?

I promise you its just low freon. Spend $5 at Walmart and put a 12oz can in, you'll be happy you did.
The temp was 87 degrees with 47% humidity.
Here's the a pic of the gauges.
https://imgur.com/a/Pyb355N
I had already added a can of freon. I did notice that the compressor makes kinda a winding noise when it's engaged.

You were absolutely right!. I t was low on freon. I took it to a mechanic and halfway through of him adding the 2nd bottle it started blowing ice cold!

Re: AC is fully charged but not blowing cold air??

Posted: Thu Sep 08, 2022 3:44 pm
by harofreak00
I can't even begin to tell you how often this is misdiagnosed. For anyone else reading this, please, just listen to someone who has done it once or a hundred times before.