My car's AC makes a hissing noise when the AC is.

My air was recently charged and was working fine but I traveled 80 miles today and after 20 the air stop blowing really cold all of a sudden. I check under my hood and saw the line that connects from the compressor to the inward section of the dash was frozen like ice. Is this normal and what could the problem be?

When temp gauge is selected cold it blows out hot air.

Have you done any dash work such as replacing stereo? There is a cable that runs down from behind dash heating console to the passenger floor and attaches to a metal pully type thing. Look under the dash at passenger left foot area. There is a silver metal thing hanging down. It should have a cable attached to it. While the ac is on in cold position. Pull it towards the seat. The ac should go cold. Move it back and see if anything changes. If there is no cable attached. Pop off dash and find the cable to reattach it. Cable my just need adjusted if it is attached. This just happened to me this past weekend. Good Luck.
Tracy

My 2005 Sonata blows warm air when A/C is on. The system is fully charged with Freon and the compressor does kick on when set to A/C but yet still blows warm air. What else can I check? There does not appear to be any leaks as the system is holding pressure.

Thanks for the reply I will check the blend doors tomorrow but I do want to add that when the compressor is on the low side tubeing should be cold but it's not. Not sure if that means anything different but thought I should add that info

I don't have anything to test the high side, and I used a gauge that came with the cam of freon I used, it just indicated that the system was at the proper pressure

My air conditioner will blow warm air while in idle, but when I try to turn it on while im driving, white smoke will come from the hood. (On the top by the winshield) I'm truly hoping this can be an easy fix for me, as I am a single mom with limited funds. Could the AC be clogged? Please help!

I will have to check in the morning, but it only smokes while driving with the AC on. While in idle it just blows warm air. I haven't heard any noise. I'll double check. I just got the car and that was the only thing wrong. I thought I could deal with it, b having a1 year old in the back sweaty and crying has made me realize I really need it! Lol

I don't know the exact pressure, the gauge I used just used colors to indicate under charged, charged, or over charged. I will see if I can borrow a good gauge from someone to read exact hi and low pressure.

Thank You