Ok, Thanks Frone !!

Hopefully Pep Boy's will have it and I'll be able to fix it tonight.

Do these high and low lines come off of that air dryer thing?

 

Yea, they run into it, the low side where you are charging it at should be around the front of the engine compartment on the passenger side and have a black cap on it

 

The problem is your evaporator is freezing up. If it cools just fine at first, and then stops it's the evaporator freezing. These trucks use what is called a txv that is supposed to sense the refrigerant temp exiting the evaporator keeping the temp above 35. If this goes bad and allows the temp to drop below 32 degrees, water starts freeezing on the outside of the evaporator not allowing air to pass through. Therefor your vent temp heats up.

 

OK guys not to highjack this thread but......My A/C works fine when it in the 70s and low 80s and when running down the highway, but let it get a little warmer and idle for a minute and the air coming out of my vents starts getting warm and moist. I took it in when new and the dealer evacuated and refilled to "proper amount" and called it fixed. Well it isn't. Anyone have any ideas on how to tackle this one? I have heard that adding a little extra refrigerant will cure this but you know how that goes, more isn't always better. If someone who knows A/C can guide me I'll go "help" the dealer get it right.

 

Nick. . .you have the same issue I have. . .but a bit worse. . .the condensor is not getting enough air flow to remove the heat that is pulled out by the evaporator. . .adding an electric fan to push air over it will probably freeze you out.

I removed the stock belt driven fan on my yoda and installed dual electric fans that I wired to kick on when the compressor kicks in. I can sit in 100+ temps in traffic and I have to give a little heat cause the air is so freaking cold.

Ive been thinking about doing this exact thing to aide the stock belt fan. there is a nice space between the rad. and the IC to put a thin profile dual setup to pull through the IC, which will also pull better though the condensor gioving a little air flow to pull the heat off.

 

this is something that happes to us sometimes on the equipment. the thing that ive found to work the best is leave the fan running at high or as high as u can posibly stand for me its the third position on my truck and the adjust the temp on the dial. i dont think u are supposed to have to do it that way but it works

 

mayfair the freon charge is too low and the low side presure is down and so is the freon temp, and the reciever dryer is freezing

 

I was thinking about that, last year. The difference between your and my trucks is that they tweeked the visctronic fan programming in my truck. They have it running 100% at idle when A/C is on and even as you take off from a stop up to about 1800 RPM, my truck sounds like a big rig with the fan sucking air. I don't know if electric fans can pull any more air through than my truck already does. I noticed there was alot of air gaps around and between all the coolers, I wonder if sealing all those gaps aroundwould force the fan to pull the air through the coolers instead of around them.

 

low side pressure should only be down if the txv is bad or the low pressure switch is bad (which keep the compressor running longer than it should.)

 

Ok guy's, I bought a freon kit and tried to add freon, but it seemed like it just wouldn't go in. The gauge read just below 25 when I hooked it up, but no matter how long I pulled the trigger on the can the gauge never really moved. The can sure asa heck got cold !!

That evaporator thing turned into a block of ice. I'm trying to download pics now.