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Discussion Starter #1
I have a '97 DeVille that's in fantastic shape [like brand new] and the ONLY thing wrong with it is that the A/C doesn't blow cold.

I tried refilling it with refrigerant and the gauge is in the red, indicating that I shouldn't fill it [there's a problem, etc.]

I was told to let the engine idle for about 3 minutes with the temperature settings set to "max A/C" [which I assume means lowest temperature [60] and fans on max, pop the hood and check using the refrigerant's built-in gauge. This is exactly what I did.

What are the most likely causes of this issue?
 

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White Diamond '03 DHS (with DTS floor shift)
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Those built in gauges are useless. You need a set of gauges to get both high and low side pressure readings.Is the compressor engaging? Did you check the codes?
 

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Discussion Starter #3
I have no way to check the codes at present. Where would I get these gauges and how much should I expect to pay?
 

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2005 STS4 1SG: GM Acc Lights, Corsa, Platnium Grille, Volant
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how cant you check codes
our cars have built in diagnostics
press and hold the red temp button and off button

if the pressure is really that high it might be over pressure or theres a blockage in the system, both cases it will not work
 

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White Diamond '03 DHS (with DTS floor shift)
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You can get a set of gauges almost anyplace. Cheap set from Harbor freight for about $40 to a good set (MasterCcool, RobinAir) online or at or any auto parts store. A good set will run $100+
 

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If the AC is not running the charge in the system will still be about 100psi, possibly more. This would be in the "red zone" on the single (almost useless) gauge. If you had a gauge set you would see both gauges reading the same.

With the AC compressor running the dual gauges would read about -25 on the low side and +200 on the high.

If a low pressure code is set you have to clear it to get the compressor clutch to engage. Disconnect the battery for a few seconds is the easiest way.
 

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If you get the gauges and your pressure is still high, you might want to try and wash your condensor that is infront of your radiator. If you are stil not getting any cold air, the problem is with the compressor or the expansion valve.

Dan
 

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Discussion Starter #9
Going to get a set of gauges soon, but I reset the existing codes and ran through a drive cycle [as per GM's page] and the codes coming up are

B1312 - High Side Temp Sensor Open Circuit

and something about the driver and passenger side-view mirror sensors being "low" whatever that means.

Could that B1312 be the problem or part of it? Are the high side sensors the wires plugged into the small tubing up near the firewall [there's one on the right and one on the left] both seem to be plugged in and there is no frayed or melted wiring.
 

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White Diamond '03 DHS (with DTS floor shift)
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The high side sensor is the one on the left (drivers) side of the A/C line on the firewall. Pull the connector and jump the two pins in the connector. If it works, replace the sensor. You'll have to evacuate the system to do it, then pull a vacuum and recharge it when done.
 

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Discussion Starter #11
Pull the connector and jump the two pins in the connector. If it works, replace the sensor.
If what works?

If that sensor is dead could that be the reason my A/C isn't cold?
 

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White Diamond '03 DHS (with DTS floor shift)
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If jumping the pins on the connector makes the compressor engage, then the sensor is bad, assuming that the system is charged correctly and nothing else is wrong. I am assuming that the A/C isn't cold because the compressor is not engaging, thus you are essentially running in ECON mode.
 

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Discussion Starter #13 (Edited)
OK, jumping the sensor didn't work. I've read that to get an accurate reading from the gauges, I need to "jump" the compressor. Is there somewhere else I can do that, or just on those sensors?
 

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Hey Hey hold it right there homie I had the same problem the cause is that you let the freon get too low and the computer shut the sensor off just take your car to a mechanic that has the little machine to reset the computer it takes about 10 minutes o and take some freon the service should cost you no more than 50 dollars
 

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White Diamond '03 DHS (with DTS floor shift)
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Entering the diagnostics and clearing the codes will enable the compressor. The compressor must be operating to get pressure readings or add refrigerant.
 
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