A/C won't take a charge

[Tinman76]

2005 GT. It reads about 33-35psi on the gauge but when I try to add refrigerant it won't go up at all. Tried two different brands with their own gauge/hoses. Car running & a/c running. Almost seems like it's not getting by that Schrader valve. Anyone dealt with this before. My ac only works when it wants to lately. Seems like it's right on the line for the low limit psi switch.

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[J57ltr]

What are you using for a gauge set? You are supposed to run it on max with the fan all the way up.

[ericspecullaas]

Omg your ac system is fine its your blender doors or you ac controls. At 35psi in the system that well with in spec . If you add more in you WILL blow a seal and have no ac.

[J57ltr]

Pressure is low depending on temp, at 90*F the resting pressure will be about 100psig with 45-55psig on the low side and 250-270psig at 90F

Jeff

[Tinman76]

I did run it with the a/c on high, etc. Someone mentioned the low limit switch is around 32psi thus trying to get it up to around 38-40psi. My ac only works when it wants to and I did replace the blend door motor. Just using the gauge attached to one of those store ac charge kits.

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[Tinman76]

Pressure is low depending on temp, at 90*F the resting pressure will be about 100psig with 45-55psig on the low side and 250-270psig at 90F

Jeff

Any idea why I can't get the Freon to flow in?

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[J57ltr]

It's not pressing the shrader valve down, when you pull the trigger does the pressure go up?

[Tinman76]

It's not pressing the shrader valve down, when you pull the trigger does the pressure go up?

No drops to zero then back to 33-35psi when I release the trigger.

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[J57ltr]

Have you ever put freon in a system before? Not trying to be a smart A, it's a serious question.

[Tinman76]

Have you ever put freon in a system before? Not trying to be a smart A, it's a serious question.

Don't think I have in this car. Had it for 8-9 years now. Had ac on high and car running.

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[J57ltr]

Usually when you pull the trigger it will either go all the way up or drop to 0 as it bypasses the gauge. Did you hold the trigger down for a little bit or give up when the pressure dropped to 0? It takes a few seconds for the can to get cool as it flows into the system. I usually heat up the can by letting it set out that way it builds more pressure in the can is cold then the pressure in the can will be lower and take longer to fill.

[ericspecullaas]

Try this turn the can upside down it will force the liquid into the system. And bring you up to 38 also revving the engine helps suck in more. I still think its your ac cluster at fault.

[RivMan]

Go to your local autozone and borrow a set of gauges, take a look at both the high and low side pressures, and see where they are with the AC on, and with the car off.

You can't get enough information from a single gauge to figure out what's going on, and AutoZone will let you borrow the good gauges.

-Rob

[mguzzo]

I had a hose with gage and trigger that came with a can of refrigerant. When fitted to a new can, the plastic trigger would hit the side of the can before it would depress the valve in the trigger mechanism. I used a wide bladed screwdriver to help push the metal valve.

[Tinman76]

Go to your local autozone and borrow a set of gauges, take a look at both the high and low side pressures, and see where they are with the AC on, and with the car off.

You can't get enough information from a single gauge to figure out what's going on, and AutoZone will let you borrow the good gauges.

-Rob

Awesome. Thanks for the info. Will do and advise.

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[Bronco Boy]

It's not pressing the shrader valve down,

^ This. My buddy does my A/C, and the last time he did a re-charge foe me, he had issues with one the the schrader valves (I think it was the one on the drivers side). He replaced it and the charge went smooth. He told me it was common on GM vehicles.