: My A/C quit, need advice...



gfourth
06-15-08, 04:34 PM
Well my A/C stopped working on the way home today, and it just happens to be hotter than hell.

I was driving along and the screen said "Service A/C system" or something along those lines, and it will not let me turn on the A/C anymore. Now I know that it is probably protecting itself from further damage, but I would like to at least try to put some refrigerant in it to see if it is low/has leak.

I am still under warranty, but I would like to do this in the mean time before it goes in.

So my question is....... I have the tool to add/read psi for the refrigerant, and I have used it a lot on my f150, but I just want to see if there is anything special I need to know about the V?

If I add refrigerant (if it is indeed low or leaking) will the compressor kick back on? Or do I need to reset the warning somehow?? With the A/C off, the low pressure side is reading 100psi (which is REALLY high, correct?), but I am assuming it is that high because the pump is disengaged and it is hot under the hood.

Thanks for any help.

2004ctsv
06-15-08, 06:01 PM
At 100 psi, the compressor should kick on. The system temp is probably over 80F to get that pressure.

The compressor has a low pressure switch. It could be bad. Or may be something else.


Vapor pressure (at 50 C or 122 F) : 191.44982 psi
Vapor pressure (at 20 C or 68 F) : 82.67151 psi
Vapor pressure (at 5 C or 41 F) : 50.76321 psi
Vapor pressure (at 15 C or 59 F) : 71.06849 psi

gfourth
06-15-08, 06:49 PM
At 100 psi, the compressor should kick on. The system temp is probably over 80F to get that pressure.

The compressor has a low pressure switch. It could be bad. Or may be something else.


Vapor pressure (at 50 C or 122 F) : 191.44982 psi
Vapor pressure (at 20 C or 68 F) : 82.67151 psi
Vapor pressure (at 5 C or 41 F) : 50.76321 psi
Vapor pressure (at 15 C or 59 F) : 71.06849 psi

Thank you for the response. I was thinking there's a leak, because ever since I got the car I always thought to myself that the A/C just didn't seem that cold, and then today it quit working. So since it quit working, I was assuming it was because the pressure dropped too low, and now the car is preventing the compressor from kicking on. I am usually wrong 99% of the time when I try and self-diagnose, so we'll see.

gfourth
06-15-08, 07:14 PM
So I was going to try and add some refrigerant, but now the low side is reading almost 200psi. I guess this gives me more motivation to take it to the dealer....

perfect
06-16-08, 08:24 AM
for what it's worth my V's AC is always ICE cold

seriously, I usually have to turn it off or redirect the vents even on "1".

good luck!

rand49er
06-16-08, 09:15 AM
for what it's worth my V's AC is always ICE cold

seriously, I usually have to turn it off or redirect the vents even on "1".

good luck!Yeah, that sucker should make your nipples hard. :D

LUVMY04V
06-16-08, 09:41 AM
All gm vehicles will shut down the ac when freon gets low from my knowledge. I would try to refill it and then unplug your battery to reset the ecu

Disclaimer: this is common sense info and should not be considered as technical LOL

gfourth
06-16-08, 10:29 AM
Thanks guys. I figured it should be ice, nipple-hardening cold, but I never put too much thought into it. I will try unhooking the battery, and see if that will reset the warning so I can put some refrigerant in it. If I can't get the compressor to kick on then I can't really do much about it until I bring it in.

LUVMY04V
06-16-08, 10:32 AM
Thanks guys. I figured it should be ice, nipple-hardening cold, but I never put too much thought into it. I will try unhooking the battery, and see if that will reset the warning so I can put some refrigerant in it. If I can't get the compressor to kick on then I can't really do much about it until I bring it in.
no put coolent in first then reset the ecu.

it will shut down the compressor when levels are low to make sure it doesnt run w/out coolent.

at least thats how all my gm's have worked. But the caddy has a fancy light to tell you whats going on or so it sounds like

gfourth
06-16-08, 04:05 PM
I went ahead and scheduled a service appointment for tomorrow. There's a few other things that I need looked at anyway. MMs, rear end whining, hard to get into 1st and R, etc... We'll see how that goes...

Thanks for the help guys.