AC low pressure isde is 150psi

[nicholas]

Hi guys well my AC died on the hottest day of the year so far,
2004 mazda3 with 80,000miles. I went home and tested the low pressure side and it spiked up to 150 psi with the engine off and on.
Just wondering what this could mean ? - It was working fine otherwise up to today.

Cheers
nik

 

[meangreen01]

Compressor not engaged. Check fuse first.

Any way you could have the hoses reversed? IDK how/if thats possible though as they're different sized couplings.

 

[scurvy]

150 psi in the low side is WAY too high, unless the system was up to 45°C. Check this table to see what the steady state pressure (AC off, system equilibrated) should be at what temperature. Probably a good idea to check in the morning before you start the car and use an infrared thermometer on the system pipes.

 

[antonmnster]

150 might be normal if the compressor was not running. More info, please.

 

[Chris142]

Originally Posted By: antonmnster
150 might be normal if the compressor was not running. More info, please.
x2 and if the compressor is running get a high side pressure too.

 

[lewdwig]

The heat's not getting removed from the system, do they have a thermostatic expansion valve?

(My geothermal system quit running last weekend because the loop pumps weren't running to remove the heat from the house).

 

[nicholas]

its the low side for sure - I have checked it before last summer.
anyway I will take it in and see what they say ??

cheers
nick

 

[mechtech2]

Why hide the information that the guys need, and even after it was asked for ?
Under what conditions was this pressure checked?
There are conditions that would make this pressure OK on the low side.
[But not while the compressor is engaged in a running state.]

 

[meangreen01]

At least check the fuse before you bring it in.