1988 Jeep Cherokee 4.0l 4x4

A/C was fully converted to r134 professionally
A/c has full freon (Evaced and recharged 2 days ago after fixing the leak that was found.


My question is that the compressor seems do disengage while driving sometimes. There's times it won't do it at all while driving. Other time it will do it multiple times. Sometimes if I play with the on/off switch it will kick on. What I usually do is when I notice it getting warmer I'll turn the a/c off, drive about half a mile and turn it on and It will start to cool again.


Could it be the clutch or a sensor/relay? Maybe switch? Any help would be appreciated.

 

BUMP need help figuring this out guys

 

Sounds to me like its doing what its supposed to. you could try a new cycling switch.

 

I'm pretty green here. (although I have mine working on propane!). Just I wanted to point out that there is a switch that will prevent the compressor from engaging if the pressure is wrong. If I had paid to have it evaced, and recharged I might consider checking with them...just a thought!

There ARE some guys here who are pretty sharp on that..good luck!

 

+1, take it back to be re-fixed.

 

I'm trying cipher here........is there possibly more than 2 days between the conversion and the repair? Was the repair also done professionally? A professional would know that the ratio/amount of oil-2-refrigerant is very important in r134a systems.

 

It was professionally converted in 2010, the OEM equipment was used when it was converted. I bought the Jeep in March of 2011 with non working a/c. The previous owner had it sitting for 6 months and the seals got worn out and leaked.

In may of 2011 I bought a.self recharge kit with enough freon to properly recharge it. It held for about 2 months.

Here's more current- May of 2012 I payed about $106 for the evacuated and recharge at Mineke. It held a/c for about 1 month and went away. I figured when I got enough money I'd go back and have them Re do it. About 3 weeks ago they told me they would Re do it for free because I found the main line coming off the compressor was completely loose and if you wiggled it it would hiss from the freon pressure.


The thing is that the A/C has done this every single time its had freon in it. Sometime it will dissengage other times it wont do it all day.




From experience on other vehicles i know if the lfreon levels are too low it will not kick on so it does not damage the compressor.

I have checked the connections to the compressor and they are wired a little weird. I will upload a picture when I get a chance. Not sure if the wireing is like this on these but my other vehicles are not like this.

 

Take it to a ac shop not a muffler shop...

 

R u saying when the compressor disengages, that it does not re-engage automatically, unless u fiddle with the switch/selector on the dash?

While driving, the compressor engagement/disengagement should be virtually invisible and vent temp should remain very steady (just a few degrees variance) due to the compressor cycling on/off to maintain a steady vent temp. Compressor cycling depends on several variables such as ambient temp, humidity, system pressure, etc.

When the XJ is idling, it's pretty easy to tell/hear when the compressor cycles on/off automatically as the rad efan also cycles on/off, unless coolant temp is high enough to keep the efan on constant.

 

OK I live in Phoenix, Az the temps are about 103*-110*. Every time the a/c is switched on the Efan is constantly running. I do not always need to mess with the selector switch to get it to go back on. But iv noticed that if I shut it off, drive about a 1/4 of a mile and then turn it back on it works fine. But that method does not work every time.


I do not have much money to bring it to shops right now that is why I am trying to diagnose it myself.

 

The efan is supposed to be on whenever the compressor is engaged, unless the vehicle is moving fast enough and the vehicle speed sensor has the efan turned off. When the compressor cycles off, the efan turns off unless coolant temp is high enough to keep the efan on. Have u placed a thermometer in the center dash vents and watched vent temp? I understand money is tight but at the same time it's difficult to diagnose a/c problems over the Internet. Google search a/c problems but u may still need to just live with it until u can have a pro attach pressure gauges, check electrical, check output/vent temp, etc. Again, r134a systems can be finicky when oil-2-refrigerant ratio is whacked.

Basically, the only way to know how much oil and refrigerant is in the system to start with a completely clean/dry system. Evacuating the system removes air and moisture, not oil. If u don't know how much oil remains in the system, u don't know how much oil to add back to the system........unless the system is clean/dry as it would be when starting over from square one (no oil or refrigerant).

 

You mean drain the oil from the fill hole in the compressor? Iv changed the. Fluid before on my old Chevy s10 compressor. I can purchase the gauges and equipment for about $100. I may end up doing the and evac-ing and recharging the system myself.

Its not a huge problem, I just hate when its 105*+ and the a/c kicks off for a few minutes and it gets hot in the car when my kids are with me. This is my wife's dd. My dd xj has no AC and I can deal with it myself but rather not have the kids deal with it.

 

To get all the oil out of the system, the evaporator, condenser and all lines should be flushed with the proper a/c flush solution and blown dry with compressed air, unless all are replaced with new of course. The compressor should be turned upside down to drain oil. From what I've read, the accumulator/dryer must be replaced as it can't be flushed/drained. Orifice tube/liquid line should be replaced as well.

 

Have you opened hood a see if its freezing up causing cycleing issue

 

Have not checked if its freezing up, it usually only happens when driving. I talked to the guy at the shop that did the evac and recharge and he said it could possibly be the clutch fan not pulling enough air to cool the condensor and that could be building up heat and pressure and causing it to kick on and off. But the fan clutch is pretty new so I don't think its that.