A/C only blows 60 degrees F.

[barking004]

Hello, hope you can help. I'm concerned about the vent temperature and possibly the compressor so here are my observations:
2004 ford explorer 4.6 L V8
First test
A/C off
Low pressure port reads 70 psi
High pressure port reads 70 psi
Second test
A/C full on including rear a/c, engine at idle
Low pressure steady at 40 psi ( does not cycle)
Hi pressure 175 psi but has some vibration ( assuming from compressor)
vent temperature = 60F; should be much lower?
Low pressure steel tube is cold but not frigid, hi pressure tube is hot with some vibration.
Then third test, same as above but engine at 1200 rpm
Low pressure cycles between 22 and 40 psi.
Hi pressure 175 psi.
no change in vent temperature.
todays outside temperature is 80F.

So what is wrong?
thanks for your help.

 

[Evan6ardner]

AC systems on modern vehicles will not even get below 60F.

Or if they do, i dont see how, since climate systems will display 60F as the lowest setting, and I'd assume that means the air at best will not drop below 60/62F.

 

[hasoan]

Welcome to the forum!

A/C off
Low pressure port reads 70 psi
High pressure port reads 70 psi
...
todays outside temperature is 80F.

So what is wrong?
thanks for your help.

You should be at about 90 psi when the AC is not running if its 80F outside, assuming your car and refrigerant is also that temperature. You might be low on refrigerant. google "R134a vapor pressure chart". on the other hand, maybe your car was 70F even though outside it was 80F. certainly as the car runs, the ambient temperature gets higher than the "outdoor" temperature, so the chart you may be looking at (r134a temperature pressure chart) could be difficult to follow

at any rate, the reading with the AC OFF is only useful if the car has set overnight and you test it at a known temperature. Plus, if the compressor is running, that probably means that you are not THAT low on refrigerant. so your numbers may be in error.

you said the high side is at 175 in tests 3. is the high not cycling with the compressor? or is that it's highest value?