Well the AC worked great all the way to work today, I had it on Max AC, Max Cold, and Max Fan, and it didn't cut out at all. The only thing is its about 15-20 degrees cooler this morning, and the humidity broke, so I could still have an issue with the Relay, and since it is only 10 bucks for a new one, I think I might just pick one up and see if a new one runs any cooler.

Sean

Saen it didn't take the full can did it? In my Ranger I just put bout 1/3 can in there and it woke the lil guy up real good.. Got the pressure just a bit out of the green on the high side.
Ran it all day yesterday around here and at fillup got 18.888888 MPG for the tank.. I'm good to go now <img src="/forums/images/graemlins/smile.gif" alt="" /> .
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

Well I honestly wasn't sure where I wanted the needle to be within the blue section, and I was reading in the middle of the green area after the system ran a while, so I filled it up until I hit the middle of the Blue area, which took the better part of the 14 oz can. I was a little worried about that too, since you said to only put in half of the can, but I figured it seemed reasonable to be in the middle of the target range.

Thoughts?

Sean

Ahhhh.... Cooling season has be-gain! I love this time of year. $$$$$$$$$$$$ going to the bank.
Don't use the stuff with the leak fix. How it works is that it reacts to oxygen like blood does. It coagulates. For some reason this stuff does this all over the system, gunking it up. To the point that A/C manufacturers will not warranty the components affected.
When was the last time you guys checked the filter at the evaporator? Is the condenser coil clean? And the cond fan running?
Refrigerant is pressure/temp. related. Auto systems have high and low pressure switches that cut the comp. if tripped. Yes, a low refer. charge can trip the low press. switch. But if the fan is not running and the comp. is, head pressure will rise and trip the high press. switch. If the air filter is dirty, it freezes up the evap. coil thus tripping the low press. switch due to the press./temp. relationship.
Speaking of this I have not checked either of my filters ever, go figure.

Just throwing out some change.
I do building A/C and refrigeration, not auto.

Where is this filter you speak of on a 99 Cherokee? I didn't see anything in the Haynes manual. <img src="/forums/images/graemlins/confused.gif" alt="" />


The can of R-134a as described above is already installed, so if its going to do anything bad, its too late...

The fan was always coming on, I thought the compressor was always coming on, but it turns out my ear wasn't initially as good as it is not for telling the difference while driving.

The condenser, externally is clean.

The Haynes manual referenced a sight glass too, but I am failing to find it, but then the Haynes manual is tailored more towards a 96 and earlier XJ.

Appreciate all the info; I work with Military Jet Engines, which donÆt really carry over to Jeeps too much. LOL


Sean

Sean only lately have a/c systems put filters in line.. All of them I have seen are in the "inside" or "maximum" intake near the floor.
I NEVER use my inside button. Just too noisy for my ears. That sound is one of the few I can still hear! Drives me silly (more).
So if one doesn't use the inside button he don't need to worry bout the filter.
As for your a/c...just use it, it should be ok now for a while. If it starts getting warm check with your new gauge and see what color you have at the time.. A good way to see how badly your system leaks.
I leave mine completely alone until they start getting warm then I get a new can and check em before opening the can..
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

My only plan now was to drive it, well and swap out that relay and see if the relay runs any cooler, but other than that, just drive the piss out of and enjoy the cold as long as its cold.

Sean

The AC has cut out on me a few more times when I had it on Max AC, Max Fan, and Max cold, and each time it happened this weekend I thought I could hear the compressor not switching on again, but I still hadn't replaced the relay, which I picked up this morning. I took the old one apart, and the contact looked rather burned to me, so presently I am guessing the relay reached the end of its intended service life. Unfortunately its cooler out now, so the AC compressor probably wont switch off, but I am going run it on Max all the way home (~30 minutes) and see if the relay feels any cooler when I get home. Other than that, everything seems "ok" since I topped off the charge on the system. We'll just have to wait and see....

Sean