# AC Suddenly stopped and low side pressure 150 psi while not running



## 502scs (Dec 9, 2015)

Hay gang, as stated in the title the AC suddenly stopped working on my 2014 Diesel.
First observation was that the compressor does not turn on and no voltage indications that it is even trying.
So first thing I checked was fuses and relay and those checked out.
Secondly I hooked up a pressure gauge to the low side port and discovered that the low side pressure 150 psi while running or not running.
Before I run to the dealer which seems to always end in a big bill I wanted to check with the group.
My car has 130k on it so I was not expecting this level of AC failure this early ;(


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## plano-doug (Jul 1, 2015)

502scs said:


> Hay gang, as stated in the title the AC suddenly stopped working on my 2014 Diesel.
> First observation was that the compressor does not turn on and no voltage indications that it is even trying.
> So first thing I checked was fuses and relay and those checked out.
> Secondly I hooked up a pressure gauge to the low side port and discovered that the low side pressure 150 psi while running or not running.
> ...


What's the high side pressure? With the compressor off, the system should equalize. (That may take a few minutes after the compressor is shut off.) 150 PSI seems high for the equalized level. For sure the normal (operating) low side should be well under 100.

If it stays at 150, either it's been over-filled, or perhaps it has a clog somewhere mucking things up.

Doug

.


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## 502scs (Dec 9, 2015)

plano-doug said:


> What's the high side pressure? With the compressor off, the system should equalize. (That may take a few minutes after the compressor is shut off.) 150 PSI seems high for the equalized level. For sure the normal (operating) low side should be well under 100.
> 
> If it stays at 150, either it's been over-filled, or perhaps it has a clog somewhere mucking things up.
> 
> ...


Thanks Doug,
I do not have a full gauge set only a refill gauge so I don't know what the high side reads.
As far as overfill the system has never been opened or filled. The first time the caps were off the AC ports was when I checked it.
My assumption here is that high side wont be that high with no added coolant. But I admittedly know very little on this topic.


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## snowwy66 (Nov 5, 2017)

Equalized pressure lo and hi shouldn't be above 110 - 120.

More then that and your overcharged. Too much and the compressor won't kick on.

Take it to any shop that services ac and have the job done properly. They'll drain it down. Evac. And charge with the correct amount.

It's unlawful to vent to atmosphere.


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