Air Conditioning Troubleshooting

[adamsry]

Ok my AC is not working and here in South Carolina we have been having some unusual weather one week it is 30F the next 80. Well 2 weeks ago i was on a road trip for 5 hours and the climate control worked beautifully, now it does not ugg. The AC Compressor is engaging but no cold air.. the vehicle is a 2000 C230 Kompressor. Logic would leave me to believe is the pressure is so low the compressor would not engage?? I have a set of pressure gauges for AC work and the low pressure side is in the normal ranges but the high pressure side is not normal but very low. My suspicion is a possible expansion valve issue but if that were to be stuck then again wouldn't the high pressure switch kick off and disengage the compressor as a fail safe? The vehicle has only 47,XXX miles so im a bit bewildered with this. The climate control system is the manual one with the round dials so unfortunately i don't have the convenience of using the high falutin test programs that you auto ac users have.

I have checked all the visible AC lines under the car and i don't see any oil residue at any connectors or any indicator of leaks and all is clean, but i'm leery as i don't want to over charge the AC system.

Normally in this case you could check the view port on the receiver dryer ohh but this car was a creation of Chrysler genius there is no view port to see if any refrigerant is circulating.

Taking the car to the stealer is out of the question at 123.00 an hour those phuckers. If any of you have experienced a similar issue let me know pleeeze.

PS the AC cabin filter has been replaced and even when the compressor is running nether the high pressure line is getting hot nor low pressure cold.

[xvvvz]

So after a while, you don't get the flashing red light on EC button?

FWIW, my compressor barfed at 30k. I couldn't belive it. FWIW (and probably not much), the dealer said that age is as much of a factor as mileage. Find a good qualified indy MB mechanic and you will save a good chunk of change compared to the dealer. Note that I wrote good and qualified ;)

[anf6789]

check on the drivers side of the car, my c280 has a thing (window) that you can see fluid run through when the ac is on. it is in front of the abs brake line distribution box, and directly below. dunno if that helps

[adamsry]

ANF6789- What your talking about is the Receiver Dryer that device on any Older Merc has the view glass but the new ones don't. Evidently if you have a star diagnostics computer you can see all kinds of goodies regarding the AC as well as other systems in the car hence the reason newer vehicles have this call it feature removed. Sounds more like requirement in schlepping your benz to the dealer

[adamsry]

xvvvz - well so far i have not gotten the flashing ec light typically that means the compressor is shut down due to failure or in sufficient gas pressure. My compressor keeps on compressing hence my confusion. The clutch is engaged and will cycle on and off when you turn the ac on and off.

[Cru328prod]

haha i got raped by the dealer yesturday, theres some kind of suction hose missing with mines, he told me. Can't figure out were it is. I would say goto a regular a/c tech and have them dye it to see if you have leaky hose....mines went bad 2

[adamsry]

There is a hose that connects to the compressor and then goes to the firewall and it appears that it ties into the fuel rail?? I'm not quite so sure what it is almost like a mini condenser but for fuel???

What ever it is when i pulled a price on it the bad boy is all most 500 so i hope that refrigerant line is not bad.

The only vacuum lines that I'm aware of regarding ac functionality has to do with the vent distribution in the cabin. (Been There and tamed that Demon)

[Cru328prod]

I WANT THAT TO HAPPEN SOON!!! So i can pull extended warrenty on that 2. Thats a vacumme line your taking about thats connected to the fuel rail i think. It connects to the fuel pressure regulator to the intake manifold.

[adamsry]

Yeppp that be the one at first i thought i was nutz when i saw it. The AC Schematics that i have for this car seem to have omitted this piece. Im assuming it is an emissions thing probably for the US ? not sure though. I suspect that it is the culprit but i don't want to get blasted in the face with the fuel. What is unusual about the part is it is not even really listed as being a part of any system in the vehicle and considering what is connects to it defiantly is something.

[Cru328prod]

Take pics, if you pull the vac line out the fuel pressure reg, you won't be splashed in the face with fuel.