I filled it up with r134a and bought the one with the gauge so I filled it all the way till almost in red on the gauge, it was just a little low from checking it before adding, so my a/c is cool but it isnt COLD, I've put it on max a/c and it gets cool but never cold enough I have to turn it down I can run it full blast and it feels maybe 67 degrees coming through, never changes. So today I went to oreiley's auto parts and bought a new low pressure switch because I read they can go bad and cause it to not put out cold air, i installed and didnt change anything??? THE PIPE IN THE ENGINE BAY IS COLD TO THE TOUCH, SO A/C IS WORKING IT JUST ISNT COLD LIKE IT USE TO BE WITH FULL R134A?????? just added it as of yesterday
A/C recharged full, pipe cold, air flow is cool*** but not COLD???
- Thread starter kosmos
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The gauge that came with the r134a can has green spot/red spot, it already has some in it so it was about middle ways, i filled it to the last part of the green before it hit the red zone, so it was safe....... and I heard it kick on but never heard it kick off
Pearl02
Member
Check your heater control valve. Make sure the valve is completely closed when the temp setting is on cold. If the valve is partially open, it is allowing some heat to come thru the vents not letting the car to cool down all the way. I haven't looked to see how easy it is to get to heater control valve. You could also have a problem with your vent blend doors. You can also check your condensor for blockage and spray it down with water. Pearl02.
I got in my car early this morning around 9:00am and drove after car sit all night, turned the a/c on and it was ICE COLD, stopped at a gas station turned car off, came back out and got in car, turned back on and drove off turned a/c back on and COOL AIR ONLY EVEN AFTER DRIVING 10 MINUTES, really weird it worked like a charm this morning but once i stopped and turned the car off it would put out COLD like it did when i first started the car after sitting all night, I have made 6 stops running around town and each time i've gotten back in car and turned it on again its the samething COOL AIR, nothing like it was this morning it was so cold I had to turn it down??????? weird????
RedDaemon
10 Year Member
that means you most likely over charged the system if it is working now. glad to see it is working 
Those kits like you use only show the pressure on the low side, right? I personally don't think you can charge the AC system correctly looking only at the low pressure side. You really need to see the pressure on the high side and have the correct pressure/ambient temperature chart. So exactly what is the pressure on the low side now, and at what ambient temperature?
fast97gt
Active Member
youve definitly over charged it. our cars only require 2lbs. or so. also if you bought the kit with the oil in the refrigerant can with the 134, you could have too much oil in the system. (only requires 4ozs.) if you didnt do this, id take it down the your local shop and evacuate the sysem and have them recharge it using there guages, and to double check the proper weight.
BlueStang73
New Member
im having the same prob as kosmos but only thing is everything works except the compressor engages for all of 3-5 secs then cuts off and repeats. yet the system is charged and no cool or cold air.
Ac systems should be checked and charged by somebody who understands them and has the proper equipment and no the crap they sell at autozone with the color guage is not accurate and as said above if you get the one with oil then the system will have to much oil which can lead to compressor failure, if a system is under or overcharged then it will not cool.
Low side lines should be cold, high side lines should be hot find the lines that go into the evaporator they should be on the firewall somewhere the low side line (larger diamater one) should be very cold and the high side (small diameter) should be warm. The evaporator is what the blower blows air across and cools the air so checking the lines you can get an idea of status of cool the evaporator may be.
My advise if you dont know what your doing its best to pay somebody who does and save yourself the headache of a failed compressor which usally causes multpile ac componet failure when the do.
Low side lines should be cold, high side lines should be hot find the lines that go into the evaporator they should be on the firewall somewhere the low side line (larger diamater one) should be very cold and the high side (small diameter) should be warm. The evaporator is what the blower blows air across and cools the air so checking the lines you can get an idea of status of cool the evaporator may be.
My advise if you dont know what your doing its best to pay somebody who does and save yourself the headache of a failed compressor which usally causes multpile ac componet failure when the do.
wmburns
SN Certified Technician
Compressor turning on/off means low pressure. Most ppl would respond with, "add more Freon".
However, this is were an understanding of the AC systems comes into play. For example, if the pressure is low even after adding enough Freon, then things such as not enough air flow or a say an obstruction in the suction line can cause low pressure.
There is a correct Freon charge. Adding too much Freon will hurt the system's performance (the Freon must have room to expand). Too much Freon will also increase the load on the compressor leading to failure.
It is only reasonable to expect adding Freon to restore AC function if the REST of the system is working as designed.
So If you must work on you own AC, start first by CLEANING the coils. Check the FANS to be sure they are moving enough air. Make sure the inside fan is on the max setting.
Finally, remember that if it is 100 degress outside and the car is idling, the system is not going to cool as well as driving down the highway (read AIR FLOW).
As another poster has mentioned, the store bought kits only monitor the low pressure side. To correctly access the system's operation requires taking into account the high pressure side AND the outside temperature.
kendoo130
Founding Member
Like mentioned before you probably have too much pressure in your system. The proper way is to start with a system evacuation (vacuum). The hi pressure side must be monitored to ensure correct sytem pressure. It's cheaper to pay someone that fully understands A/C systems than to replace a broken compressor because of overcharging. It was in the 90's yesterday in NY and I saw temps of around 38 deg at my center vents.
k4mjk
New Member
the system holds 2.13 pounds of r134a it has a high pressure cut off and a valve on the compressor to prevent it from blowing up
Another thing to consider is the possibility that the orifice tube has become clogged or partially torn due to overcharging or too much a/c oil. Most of our cars have the OT built into the liquid line and you have to replace the entire liquid line. It's a dealer only item and runs about $65.
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