A/C yesterday, no A/C today
 

All was fine yesterday. When I got in the car and turned it on today, no air conditioning. It blows just fine, it's just the air is hot (South Florida 85F hot). I don't know much about A/C but..... the compressor clutch is engaging, and when I pressed the needle inside the schrader valve in the a/c plumbing, it sprayed foam at me so I'll assume there is refrigerant in the lines. And ideas as to what to check?

I have that same problem with mine no AC. Anyone know how to fix it?

Come on guys, it's hot as hell down here. No one knows ANYTHING about a/c?

I'm very dissapointed in you guys. Very hot..... and very dissappointed. ;)

Hmmm, your system is charged, can you see the compressor turning? I'd check the fuse, and psi in the lines, make sure the fan is running. If still no go, then into the shop, AC fixes are either cheap or new compressor :(

I couldn't tell you quantitatively how much pressure is in the line, but when I touched the needle some white foam shot about three feet into the air, so I'll assume there is both sufficient pressure and refrigerant. The clutch engages and the rpm's drop when you turn the a/c on. I don't know what else it might be other than the compressor gone bad. :(

No A/C
 

You can still have pressure without having enough refrigerant in the system. You need to take it to a shop and have them check it (unless you have the equipment to do it yourself.

Is there a hissing sound from the passenger side inside the car when the a/c switch is pushed (not when it isn't engaged)? If there is i think I can help because that is what I had. I believe I fixed it but haven't charged her up again to make sure.

duckyjp - I don't remember hearing a hissing sound, but it's damn near impossible to hear anything over the exhaust. I'll check tomorrow, but I'm interested in what you did.

Well if it's not your compressor...which it probably isn't, you have a leak of freon somewhere in your system. FD compressors don't tend to go out prematurely. I had a prob. with my AC blowing hot this past summer and took it in and found that there was a leak coming from the schrader valve, which is the valve itself where you attach the fittings to for recharging the system. Has anyone touched your AC line at all?? Mine went bad when someone checked to see how much freon I had. After that there was a slow leak from that valve.

If the compressor is still engaging then you still have enough refrigerant in the system to prevent the low pressure trip switch from cutting off the compressor.

However, that is only to protect the compressor from self destructing.

Check that the condensor fins are clear at the front of the car, wash them down with water if possible, make sure the fans engage when you turn on the A/C, if the fans don't work then efficiency will be down.

A/C has an efficiency curve when measured against amount of refrigerant in the system, it is quite steep towards the peak, so you only have a small window of the correct amount before efficiency drops off badly.

Most faults are down to loss of refrigerant, which can be the general loss through the seals and pipework over time, or failure of a seal. When did you last have it topped up? It is best to have it checked each year.

Get the system vacuumed out, if you can afford it, replace the receiver dryer, and then get it filled with the correct weight of refrigerant.

The fact it works and then doesn't, suggests that you might have moisture in the system, which can freeze and block the expansion valve. I'm afraid the only way to resolve that is to have it vacuumed out which reduced the boiling point of the water and removes it from the system. If this has happened, then you definitely want to replace the receiver/dryer!

Compressors tend to be all or nothing, usually seized or working fine.

Good Luck

-Richard

If your compressor is indeed running, check the sight glass in your receiver/dryer. It should be running clear with few or no bubbles. If you have bubbles, you need some refrigerant.
Also, depending on the system design, the expansion valve or the orifice tube could be freezing or clogged up.
Regardless, you have R-12 in there, and you need to have whatever is in your system vacuumed out and recovered, because it is damn near worth its weight in gold these days!
I think the trend you are seeing here is.....you simply need to take it to a shop. In the end, just thru lost refrigerant alone, you will be money ahead.

check the condensor first. A lot of time rocks and crap get kicked up and damage it. The weak link in the a/c system is the high pressure cooling hose (learned this from my rx7 mechanic). The walls of the hose are very thin and it is high pressure. It runs under the hood from the passenger side right near the strut tower all the way across to front of the car. Many times this metal hose (about 1/4 inch) rubs against things and isn't seated right in the brackets. I checked it out (had to remove air box, intercooler and battery but they were out anyway) and there was a lot of wear in certain spots. My mechanic said you should be able to see a pretty big hole if that is where the leak is. He said to check all along the hose but especially under the intercooler and under the battery(check to see if hose is pitted from battery acid or anything. Anyway, I didn't find a hole but it was well worn so i ordered a new one anyway for 80 bucks. When i went to change it I found that the fitting by the strut tower had somehow worked it's way loose and I believe that's where my leak was. So with the new hose and the tight fitting I should be good to go for a long time but i am not positive because i haven't taken it to the shop to get it filled and checked out.