hi, I had to use the ac today since it is over 80F and my vents are blowing warmer air than the passenger side; I tried the reset process and it is still the same. i dont think I need to recharge the AC because it is cold in the pass. side. Any ideas? thanks.

 

Does it make any clicking or hissing noise?

Do you feel a slight vibration when you slow down to stop at a stop sign or at idle when you have the a/c on?

 

not at all. works normal.

 

Mine does it off on the weird noise. Gonna have to get it done this summer. I"m thinking either Alternator, one of the Pulleys. We'll see soon.

 

IF the other side is as cold as it should be, then to me it sounds like some sort of vent isn't blending the air properly.

 

what part could be wrong then?

 

I typed in 'AC passenger side mercedes' in google and a bunch of threads came up.

It seems to be consensus that if you are low on refrigerant, it won't feel the evaporator completely up.
http://www.airconcars.com/assets/images/diagram.jpg

You can get a little low side pressure reading gauge from auto zone along with a can of R134a for idk, 20 bucks or so. Stick the gauge on the low side (easy to find), and note what the pressure should be for the temperature outside.

If its low, then, you can either add refrigerant, or you can get the kind with dye in it and use a 5 dollar ultraviolet light kit that is probably right next to the R134a on the shelf, to find if there is a leak. Sometimes using stop leak can clog stuff up. If there is a leak, try to patch it up, or replace whatever tube is leaking.

Worst case scenario if you are low on refrigerant, is that eventually if it keeps leaking you will lose too much oil that they actually add in along with the refrigerant when they first installed the system. If that happens, your compressor (look at above picture link), will not be lubricated, and can eventually fail, which costs 500 bucks used not including labor.

To prevent this you would need to use a vacuum to suck out all refrigerant or go to someone that can do this for you, take off the compressor and flush it and re add a specific oil in it, replace receiver drier at least, and then add refrigerant in. But check for a leak before you drain system.

There are other things that people like to do but I think that is the basics.

Anyway, most people don't care about all that, and just add refrigerant. If its a fast leak, fix it though, otherwise if you just keep adding refrigerant, it will definitely add up to a failed compressor eventually due to no lubrication.

If its not that, then it could be the blower behind the evaporator, a clogged evaporator, or maybe the heater is on some how. Just random things I'm intuitively thinking of, but really have no idea.

Hope that helps.

 

i will try to recharge it first

 

That happens to me too. But on the passenger side it blows out warm air. What I do is move the temp dial for the pass side from right to left at cold and it's back to normal. It happens sometimes. Don't know the cause of it. I don't think its the compressor. I believe it has something to do with the controls.

 

i will try this next time