Ok all you A/C masterminds, diagnose this.

[inline 6]

Alright..... I know just enough about A/C to get me in trouble. here is my situation.... 08' jeep wrangler. The A/C feels a little weak, it gets pretty cool but never the cold that I remember it in previous years and I have noticed a significantly reduced amount of condensation dripping off from under the vehicle. I will also note that it has had zero A/C service since it was new as well. I hooked up a set of gauges to see what was going on and with everything normalized and warmed up, the front end in the shade, and the A/C on max recirc inside, and a 102 ambient temp I was getting right at 39psi on the low side and 275psi on the high side. The temp coming out of the center vents was reading right at 50. With the ambient temp where it is I was expecting to see a little higher #'s on both sides. With my limited A/C knowledge I kind of ruled out a blockage in the system, a faulty compressor, and the condenser has been washed recently so I dont think it is a blocked condenser or clogged fins reducing its efficiency.

In my genius I decided to add a little 134 and it sucked down half of a 12oz can before I knew it and this was with me watching the low side not letting the pressure spike. My #'s then went to about 40psi on the low side and 300 on the high side. Although I noticed zero change in the temp coming out of the vents so I stopped as I was scared of overcharging the system. I am not sure at all that it is even leaking but the #'s suggest it. if it is leaking it is a very small probably undetectable leak.

Any insight on whats going on?

[inline 6]

I kinda feel the same way but I found and fixed a leak In my step dad's 02' Tahoe last year aand that thing is blowing 34 degree air out of the vents within 5 minutes of being on.

[inline 6]

Its a possibility, I need to see how hard that is to check

[jyro]

I suppose it's an electric fan on the condenser? Does it have a heater control valve for the heater core, it could be leaking. Is the suction return line to the compressor cool or cold?

[BP]

There isn't much humidity in the air (under 20% today) so you aren't going to see as much condensation as in May/April.

As for your specific case with 100 degrees outside Jeep says the low side should be between 46-70, high at 225-350 and expect 52-72 out of the center duct on high.

It was probably slightly low on refrigerant but well within specifications. I usually shoot for lower pressure on the low side but when it's more like 75-80 outside it might freeze up. Too high of head pressure can cause some serious problems though.

[inline 6]

I screwed around with it a bit too much and lost track of where I was at with it. I released the whole charge, put a vacuum on it and put in 18oz of freon which is book spec. I also added in 2oz of oil because I know it lost some when I let it out. It was blowing 54 degree air out of the vents today on the way home when my ambient was reading 109. I guess it will have to do.

[kdventura73]

Hows the airflow out of the vents? The recirculation door breaks all the time on those which could be blocking air flow to the evaporator. Pull the glove box down and see if you can see the recirculation door switch from pulling outside air to cabin air. If you cant see the door move or hear it switch, pull down the blower(3 screws) and see if its laying in the case, remove the door though the blower case. If it does need the door its cheap and you don't have to remove the dash to change it