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AC HELP IS NEEDED FROM A PRO. ASE MECHANIC HERE. ISSUES ACCEPTING REFIGERANT.

Intellect

NAXJA Forum User
Location
Tampa Florida
Fun story! Need help from an ac pro.

Xj has never had working ac. I purchased a used compressor, new evaporator, new drier, and used but good lines for from expansion to drier and compressor and to condensor.

So i have a 4.0 4wd 1995 cherokee but got a used 1992 compressor. It has different fitting sizes so i replaced my hoses with the 1992 hoses but new expansion and new drier.

I vacuum the system. It even holds pressure for a good 20 minutes, so i DID do the correct tests. I even borrowed the fancy gauges and vacuum pump. Even had an ac pro help me. Im not shy to ac work..

Well the compressor wouldnt accept any refigerant. Now i do have two problems in one, an electrical, plus the system refusing to take in refigerant. When i turn the ac on with the drier jumped, the ac clutch does NOT come on... I tried the drier jump to itself trick, didnt work. I also tried compressor to the 12v constant. The clutch kicks on when i put it to 12v battery positive , but no matter what it would not take in any refigerant.

(Fast forward a few days, if i put a jumper wire in the a/c relay uner the hood, the ac switch does turn on the ac clutch with drier jumped, thus i believe the electrical issue is just a bad relay, even though the abs relay didnt work in the ac slot.. the relays could be different even if they look the same)

Yes i oiled eveything right, yes i know a ac mechanic should only do this. Im mostly ase certified, motors engines brake suspension etc , but this ac system is kicking my ass. Expansion and driers good. I was told compressor worked when pulled, but it doesnt take any refigerant even if drier is jumped or if clutch is direct 12v.

Now my electric fan doesnt kick on either, was told these tie together electrically? Even with relay jumped and drier jumped the fan doesnt come on, but ac clutch DOES.

Also, i think the compressors bad, and i have a electric issue. Cause thats what the pro...over the internet...told me. Two issues total?

Need help and insight

Systems currently vacuumed so if it turns out to NOT be the compressor, id LOVE to be able to fix electrical ISSUES and add refigerant

But if it is.. than it is.. just need some input

Dont want to buy a $230 compressor and the system still refuse refigerant.

The used compressor was from a 92 jeep that was being parted out, so it had no hood.. ac supposedly blew cold 2 months ago.. but when i pulled the compressor it had no refigerant in it, and the firewall auminum hoses where bent and broke off on other side of the expansion valve, so air did get in the system.. but air shouldnt ruin a compressor. And water wouldve only hit the outside of compressor...

This entire situation has me stumped.

To spell it out....


I purchased a harbor freight ac gauge set and vacuum pump


Connected high and low to behind compressor car end

Connected pump

Turned pump on

Opened gauges

Vacuumed for 35 minutes

Turned gauges off, turned vacuum off

Sat for 20 minutes.. held at 29 ish blue, and as low as red would go..( this told me yay no system leaks! )

I turn vacuum on and re open gauges and vacuum it for another 40 minutes.

Everything is smooth, i go to add refigerant

I close gauges blue and red. ( Car end still open )

I undo the yellow line from vacuum pump, connect refigerant can.

I pierce can with tapper

I purge the yellow line into the atmosphere (sorry trees) (the harbor freight gauges had a cool purge button)

I think everythings going smooth

**At this point i crank jeep, and force compressor on by jumping drier and compressor to constant 12v (didnt know relay was bad back than) **

I open just the blue gauge to allow refigerant in.. i wait 20 minutes... Shake can, hold it different ways, blue gauge started mid level, than slowly climbed to about 100.. than stopped. I wait an wait and wait... Its as if the entire process was paused by a magical time button, the can will not empty out any more, the system wont take any, the vents do not get cold, the system probably accepted 2-4oz? Can got cold, but not icy, before the system refused to accept anymore... Nunbers could be off oz wise, maybe it didnt take any, i just know the can got cold and felt barely barely emptied. As if it took one tiny sip out of it.

After 25 minutes of the system literally refusing refigerant i ask my ac tech friend what to do!? He says open the red gauge. When i do this, both red and blue went to 100. He claimed "welp compressors shot"

I just want to know if that logic makes sence? Id hate to spend $230 on a compressor, and mess with the labor, and the compressor NOT be bad. But if it is for sure bad than ill bite the bullet.

This compressor supposedly blew cold two months ago... Before sitting i direct sun and rain for two months.

It has 1992 fittings but has a 2000 sticker on it. Was replaced and r134a'd built.


So in the end.. i tried to charge my ac and the system refused refiggerant even with compressor forced on..






Anothee guy thinks it is impossible to get 100psi on both gauges without me have had done the process wrong. He swears impossible, he swears i probably fudged up a step or two... But this isnt my first rodeo.

Any and all insight is helpful!!

If i can figure out how to attatch pictures, im attaching one as i tried charging... One of when it wouldnt charge and i opened high valve... And one of what the "you had to mess up" guy says. Thanks a lot guys for any help!
 
My first thought is the early XJ had a valve right where the ac lines hook up to charge. I know 91 had these valves, not sure about 92, later years went away from this design. Problem with this design is the valves have to be opened with a 8mm or 1/4 wrench for the system to accept any freon, or be vacuumed. Usuly have a plastic cap the screws over the valves so you wouldn't necessarily see anything to turn at first.
I can't find a picture on line to show what these valves look like and I have no idea what the the line it was replaced with are. 20 year old vehicles have all kinds of patch jobs through the years.


Wait here is a thread on another forum where a guy call the ac service valves, this is on a 1990 XJ, the 1991 are in a different spot and I think 1992 they started to phase them out, but it will give you an idea what I'm talking about, but I doubt it's on you jeep.
https://www.cherokeeforum.com/f2/ac-service-valves-226385/


Sent from my iPhone using Tapatalk
 
Thank you for the reply and taking the time to reply and read my long post. I clicked the link. That is NOT my set up. I have a blue cap that screws over low. But mine are on back of compressor in line in like a t formation, and are r134 quick connects.
 
Is there a way to upload my ownphoto lol? Mine doesnt look like the link... But it has a t on back of compressor. Ill upload pic... Now im curious..
 
I use tapatalk app to post pictures now, used to be a few good picture hosting sights but they either delete pictures after a time or now charge to share them.


It sounds like you might have those valves. If you do one weird problem is they can become clogged with fix a leak crap.
On the 91 those valves are positioned in such a way they don't really get noticed. They point toward the engine and can be a pain to close once the engine his hot. At least I'm burning my hand.

Found this picture of I think a 91 set up

758348eb9c5bed42d260b82d18afb97c.jpg



Sent from my iPhone using Tapatalk
 
Omg. Yes. Thats mine! I used those hoses. . I wonder if those valves have been shut. Yes. THAT looks identical. Ive besn trying to upload my engine bay for 10 minutes lol.

If those valves where shut than my vacuum test was faulty.. and so was my adding refigerant...

But not sure who would have shut them if the old owner said the ac blew cold.. but worth looking at when home.

Even if they are open, they could be gunked like you said
 
You only need to open them when charging or pulling a vacuum. They can be a pain to start turning if they are stuck and can be clogged if stop leak was used by a previous owner.


Sent from my iPhone using Tapatalk
 
Omg i bet they where shut than. I feel so embarrassed! That makes total sence. Because you say they stay closed unless charging or vacuumed. I pulled the lines and compressor. But never touched those valves. So they were probably shut. I. Cant. Believe this lmao. Im checking this right after work.

If there shut than my vacuum was only testing the gauge lines lol, and no wonder refigerant would not go in.


I cant believe 3 ac techs overlooked this. You sir. Are amazing.
 
I'm not surprised techs missed this it was antiquated in the 80s, I guess jeep kept with it until all the parts in stock were used. No reason for them to be on a 1990s vehicle.




Sent from my iPhone using Tapatalk
 
...and to open the valve... you turn it clockwise, like you're tightening it, to close the valve opposite. Rightie/loosey Leftie/tighty
 
Don't forget, put the valve back to its current position after charging....Leaving it "full open" blocks the flow of refrigerant and you can blow up the compressor.

These systems are way easier to charge with a machine instead of gauges.
 
Thanks paradise and thanks John for the replies.

Update: now that it's operating like a familiar animal a vacuum and die test showed the condensor was cracked and leaking. Ordered a new one. Pick it up today. Installing it tonight, hopefully have time to charge the system too.

Went ahead and warrantied the new drier thats been exposed to air fot a few days now too.

Expansion is far upstream so it should be fine having sat for 3 days.


As for those retard valves, i found out quick that they are reverse. A pair of vice grips opened them up with a little persuasion.

Fingers crossed.
 
the valves have 3 modes. full closed shuts the service ports. full open closes the a/c lines from the compressor so you can check the oil and replace. partial is the charging and servicing mode.

i usually give them one turn maybe 2. and make sure to close them after.
 
the valves have 3 modes. full closed shuts the service ports. full open closes the a/c lines from the compressor so you can check the oil and replace. partial is the charging and servicing mode.

i usually give them one turn maybe 2. and make sure to close them after.

That's what I was trying to convey....you made it much clearer. :thumbup:
 
Thats odd, i have them turned 4 times ish, and the compressor WASNT shut off to valves, cause it pushed the leak uv stuff through the system just fine. Thank you. Did not realize it had three functions. Thought opened and shut. Didnt realize partial is where i wanted them.. kind of scary that there is no indicator.

I assume they are at the "partial" stage with my 4 turns though if i got the uv leak all the way to the condensor right? (Where my leak was)

Im guessing my turns where around 4 total, vice grips and 1/10th of a turn at a time , mine are about rounded off from previous owner.. they work fine, but are annoyingly rounded.

But in the end, they could have turned more, plus i got uv leak to the condensor through the compressor, so i assume im at that "2nd position" i want to be in for servicing.




Wow yall are amazingly helpful!
 
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