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i have a sonata limited with a 2.4 and a month ago my ac broke so took it to a rad place and they changed the condenser there was a leak I could see it. all was great for awhile yesterday I lost cold air only warm so took it back and we checked the pressure and on the low side there is 95psd but still no cold air.
when I turn ac on the cooling fan comes on and I unplug the compressor to see if there is voltage and 11.45 and when I put ac on the idle goes up a bit when the cooling fan comes on voltage goes up but still no a/c. if there was any sensor that would still be voltage at compressor. thanks
 

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Put gauges on the system, both low and high sides, and crank it up, max low temp and see if the gauges change.
If they change only slightly, compressor not doing its job, probably the electronic valve in the back of the compressor, replace compressor.


Check also to make certain pins/tabs aren't sheared off.
Problem with these compressors is that oil is needed to lubricate the compressor even when a/c off as compressor internals are turning all the time. So if refrigerant is lost, compressor continually runs and locks up from lack of lubricant, the pins on the pulley will break loose and only the pulley turns, but internals won't. Another compressor needed.
 

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.....we checked the pressure and on the low side there is 95psd but still no cold air........
95 psi is more than twice normal on low side, without knowing high side pressure it’s hard to determine what might be the problem. But with low side that high there is a problem.
 

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we did that this morning and there was no change when we were pressing on the ac button
If you have the correct pressure 95 w/o a/c running and 12 volts, compressor gone.
Not certain as to what you did this morning? Checked pressures with both sides connected to gauges and/or checked for broken pulley pin and compressor shaft not turning?
Bottom line, I'd say another compressor needed.

95 psi is more than twice normal on low side, without knowing high side pressure it’s hard to determine what might be the problem. But with low side that high there is a problem.
Probably the 95 psi on the low side is when the system is at idle, no compressor action, and if a reading was taken on the high side, it would be @95 also.


I want to also add, if indeed the compressor locked up and only the pulley is turning, then a complete cleaning/replacement of the system might be needed if any debris found when opened up.
 

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If 95psi is compressor off, then it'll be the same on either hi/lo side.

Compressor and thermistor failure are common. I was just in a newer Elantra rental from the airport at is had no A/C.... dash temp read 45F when it was 100F.... compressor kicked in whenever it wanted which wasn't enough. Had to swap it out for another rental. If your compressor isn't pumping(and it can be heard from inside the vehicle), and it has voltage(not the thermistor, pressure, or dash switch), then compressor has failed. But, I wonder if it would respond to higher voltage with jumper wires from battery directly??? Or, bleed out some of the non-running PSI from 95 to 85psi.

Amazon and rockauto have compressor kits. Don't forget to replace the filter/drier, seals....
 

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bad compressor. Ac system is engaging (fans, higher idle...etc) your not getting operation at the compressor. 95PSI at warm IDLE state for low side to be expected as low and high side will equalize. Compressor kicks on, low side 25-40 PSI most systems. High side 150-200 ISH


Change the Compressor


EDIT: many compressor / ac threads, go back and look. I posted the TSB how to diagnose Our Variable Load compressors. dealer uses Jumper harness and HDS.
 

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where is the thermistor
Thermistor in high side @ the windshield washer reservoir. The evap sensor can also be checked at various temps, but end result is well stated below....................

bad compressor.

Change the Compressor

Once again, make certain the compressor didn't go south from lack of oil and distribute debris throughout the system
 
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