Hi, I have noticed a weird odor in the cab, yesterday the air stopped cooling.
The odor was a chemical smell, have smelled it for a while. I know the dash was removed and the coil or evaporator was replaced years ago, truck has 140k on it.
I noticed the top metal ac line was froze up. Does anyone know what this could be? I looked under the dash and it is just packed full. I could not see anything.
I find it unlikely that the dash is goings to have to be removed again. I hope there might be a loose connection under the dash.

Thanks for comments

 

Have an a/c shop take a look. Could have a leak. Is the smell antifreeze?

 

No, it is weird chemical smell. I read that freon does not smell like anything but that is what I thought it was. I thought it might have been a possible mold issue but then the ac quit so I thought it was freon. I turned the air off and used the windows for cooling, the smell went away.
I am just trying to get an idea of what it could be because I don't want a big surprise from the dealership.
John

 

Your dash needs to come out again. Most likely a leaky evaporator. The r134a may not have an odor, but the PAG oil sure as hell does. It's not a good smell. You know where the water drains out of the evaporator case? Look for yellow/green UV dye dripping out. You can also look around under the dash for the dye.

There is a very remote chance that there's a loose connection - but typically the O-rings at those joints don't leak until they've been disturbed, which is why they should be replaced whenever they're exposed. The fact that it's been years leads me to believe that it's unlikely that it's anything but a bad evaporator.