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Hi,
So I have an 02 TB just crossed 150k the ac issue I’m having is it runs down to 45F and is usually fine unless the temp is hot outside over 80f. Or it will be cold for about 20/30 min then won’t blow cold. I have checked the Freon level it is full. The compressor will kick on and off. I have heard about getting the system pcm flashed By dealer. Where is the air intake for the cabin is it On the dash just outside the windshield? Also does the 02 TB have a high pressure cut out? Is there any sensor for cabin air temp? Finally does the ambient air temp sensor tie at all the the AC temp? Thanks again sorry for so many questions.
Sounds to me, like you have a low amount of Freon in the system.
Someone probably didn't shake the can, and forgot to hold the can up-side down.
Which causes Compressed air to go into your system, instead of the Freon.
( you check the pressure with the gauge of the can, while can is up-side...up.)
Watch a youtube video on it, keep in mind depending on the vehicle, Most have to be running full blast while filling.


If you live in a very hot state, or haven't driven in awhile.
don't turn your AC on Full blast cool right away in the hot summer, otherwise you will get too much condensation/moisture.
Turn it to slightly below medium (70) for about 2 minutes on high, and then cold.
 

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2002 Chevy Trailblazer LT
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Discussion Starter #22
Thanks, I got a can of ac pro and when I hooked it up it was showing completely full. My uncle was there and he has been a heating AC tech for 30 years. It ran fine yesterday and was cool. It just something about the outdoor temperature being over 80-85 degrees. Once that happens the compressor won’t engage.
 

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Thanks, I got a can of ac pro and when I hooked it up it was showing completely full. My uncle was there and he has been a heating AC tech for 30 years. It ran fine yesterday and was cool. It just something about the outdoor temperature being over 80-85 degrees. Once that happens the compressor won’t engage.
It shows pressure , it doesn't show how much freon you have.... you have to release the pressure out of the system and redo it.
30 years doesn't mean much......
I've been to a mechanic that's had 40 years experience and doesnt know what orange water with sparkles over flowing out of a coolant reservoir is. (Rusty radiator).

Ive also met a mechanic with 32 years experience , that put car tires on backwards , because he didnt know what directional tires were.


Just saying , things change , and anyone can learn something new every day.

Especially instructions on freon.
I've seen this done wrong 100s of times.
 

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Sounds to me, like you have a low amount of Freon in the system.
Someone probably didn't shake the can, and forgot to hold the can up-side down.
Which causes Compressed air to go into your system, instead of the Freon.
( you check the pressure with the gauge of the can, while can is up-side...up.)
Watch a youtube video on it, keep in mind depending on the vehicle, Most have to be running full blast while filling.


If you live in a very hot state, or haven't driven in awhile.
don't turn your AC on Full blast cool right away in the hot summer, otherwise you will get too much condensation/moisture.
Turn it to slightly below medium (70) for about 2 minutes on high, and then cold.
"Shake the can"? Wha-a-a-a?
How much compressed air do you suppose is in a can of Freon?
Ya gotta watch out... that sneaky ol' air can crawl in through the threads on the fittings too ... especially when the system's under pressure........ not!.

The rest of your statement .....ehm... .. er...... [faceplant]
 

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"Shake the can"? Wha-a-a-a?
How much compressed air do you suppose is in a can of Freon?
Ya gotta watch out... that sneaky ol' air can crawl in through the threads on the fittings too ... especially when the system's under pressure........ not!.

The rest of your statement .....ehm... .. er...... [faceplant]
Just youtube and watch the difference between an up side up can , vs a shaken can up side down. The results will confirm the information I provided.

Just like whip cream .
 

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2004 chevy trailblazer_lt
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...and everything on the internet is fact! NOT. There is zero air in a can of R-134a unless it was tampered with. Shaking the can might vaporize a very small amount of the liquid R-134a that is left in an almost empty can of R-134a. However, it's not very wise to add liquid R-134a to the vapor (low pressure side) of an automotive AC system.
 

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2002 chevy trailblazer_lt
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I suspect the inverted can thing is brought over from other refrigerants that are azeotropic blends like r410a Puron. These require charging liquid to maintain the proper proportions of the mixed refrigerants. R134a however is a pure refrigerant, not a blend and thus does not require inversion.

Now some cans may have additives, sealers, and god only knows what else they add to make a marketing claim and those manufacturers may want that crap shaken up! ;)
 

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2004 chevy trailblazer_ls
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These vehicles have a high pressure switch in the line near the compressor. You'll need a high end scanner or a tech 2 to check it, may be the cause of your problems.
 
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