'99 New A/C but still not cold enough

So as the title says my AC isn't very cold. I just recently put in a new evap core and then had a buddy of mine evap and recarge it at his shop. The air coming out is cool at best but it isn't "cold". I had done this same thing to my '97 back a couple years ago and after it was charged the AC threw ice at you (it was really cold) so i guess i assumed that i would get a similar out come. The only thing that I did different on this repair was I didn't replace the receiver/drier. The system holds pressure and doesn't have any leaks, the compressor cycles as it should and the electric fan kicks on, so before i rip it apart again i would like to get some feed back on this. Any help would be greatly appreciated:helpme:

Is the drier getting ice cold? If so I would suspect the a/c-heat blend door isn't working properly.

Now that you mention that, rigt after i put it all back together i was having issues with that door it got stuck on the heat and wouldnt turn back. I guess in the newer ones they have a motor instead of a cable so i had to turn it by hand back to the cold side. Since then i havent had issuses with it but that would make sence. I really dont want to pull the dash again to find out.

Oh and about the drier, I checked it right as i was headed to work and yes it gets dang cold.

Any time you have the system open, as yours was you need to replace the accumulator. Not replacing it may not immediately effect the cooling but if the desiccant bag is satuarated with moisture and can't remove moisture from the refrigerant, it can lead to corrosion from the water reacting with the refrigerant to form acid down the road. While you were at it you should have replaced the fixed orifice tube. If it's partially plugged it can effect your pressure.

Have someone with a set of manifold gauges check your low and high side pressures.

Well i checked with a guage I had and it indecated that i was a little low. So i bought a can an filled it up but now the air isnt cold at all!!!!! Lines to the accumulator used to frost over but after the accumlutaor they were just a little cold. Now the lines to the acc are just a little chilled and after it the lines arent cool at all. I was worried that there might be a problem with the acc, looks like ill have to replace that too.

Weebur do you know where the orifice tube is on the '99? If im ripping it apart i might as well replace that too.

Sounds a lot like what mine was doing....

I had the system evacuated and recharged due to miniscule ongoing leak, that I don't want to sink an lot of money into. It's to the point where an AC charge will last me two years.

Once the system was recharged, I still had an issue with it not blowing cold. The AC tech told me my Low Pressure switch was bad, but since I had an aftermarket one previously installed, he was going to hunt a similar one down, or charge me for a new OEM Low Pressure switch and new wire plug ($140 :shocked: ), since the old plug was cut off.

I went back to the orginal place that swapped in the aftermarket low pressure switch, and bough a new one for $20. It's a simple unscrew / screw back in deal, with no loss of refrigerant. Blows nice and cold now....

BTW...the new Low Pressure Switch (which mounts on top of the drier / accumulator) is adjustable, so that you can dial in the pressure when your AC system kicks in....

BTW...the new Low Pressure Switch (which mounts on top of the drier / accumulator) is adjustable, so that you can dial in the pressure when your AC system kicks in.

Click to expand...

How is it adjustable? Or is that for your aftermarket one?
Also, my compressor kicks in just fine, i thougt the switch was a saftey to keep from ruining your comoressor.

Im going with what Weebur was talking about that the accumulator needs to be replaced.

Jeepedo129 said:

Well i checked with a guage I had and it indecated that i was a little low. So i bought a can an filled it up but now the air isnt cold at all!!!!! Lines to the accumulator used to frost over but after the accumlutaor they were just a little cold. Now the lines to the acc are just a little chilled and after it the lines arent cool at all. I was worried that there might be a problem with the acc, looks like ill have to replace that too.

Weebur do you know where the orifice tube is on the '99? If im ripping it apart i might as well replace that too.

Click to expand...

Mine is located in the line that runs from the condenser to the evaporator. My original fixed orifice tube was replacable (about $25 for a premium one), later, when I had to remove the original line during my quest for a perfect system it kinked. I had to buy a new line (~$40) and the replacement one had the fixed orifice tube further down the line and it's not removable.

Leave the plastic caps that will come with the new accumulator on until you're ready to add oil and hook it up. Use Q-Tips soaked with PAG100 oil to clean out the females ends of the lines and the "new" O-rings on the male ends. Also leave the cap on the oil container on at all times between cleaning the lines and adding oil to the accumulator.

97-99 Cherokees use about 20oz of refrigerant (don't think putting any more that that will make it run cooler...it won't). An overcharged system can have the same symptoms as a system that is under charged. And, having an overcharged system is hard on everything, especially the compressor.

You'll need to add 4oz of PAG100 oil to the new accumulator. Your system require about 8oz of oil (total). Having too much oil in the system will make it ineffcient and too little can damage the compressor. Pick up a very small funnel to add the oil.

Doing this kind of work is doable, if you take your time and do it right the first time. When you're done you MUST have the system evacuated with a vacuum pump and depending on your altitude your system should be under vacuum of 26-29in/Hg for about an hour. This has to be done through a set of manifold gauges. Then you should turn off the pump and close both the low and high side valves on the manifold gauge and let the system stand for about five minutes. If the vacuum doesn't drop for five minutes the continue evacuating for ten more minutes. Now you're ready to charge the system.

As a side note: The vacuum lowers the boiling point of any water in the system and turns it into vapor and then sucks it out. When you're sure your system is tight then add 20oz of R134a. Doing it the absolute right way would include replacing both Schrader valves and flushing the evaporator and condenser...but you should be OK.

Unless you have a pump and gauges I suggest that once your system is hooked up you take it to an AC shop and have them evacuate and charge your system.