2nd Gen Non-Engine/Transmission AC stopped working system full ?

[jmos4]

Hi,



I have a 99 that one morning the AC stopped working, worked great the day before,, just checked the PSI and the system is full, the clutch will engage for maybe 30 seconds and disengage



I replaced both the high and low PSI sensors and no change as well as tried to add more R134A and would not take any more, any ideas?



Regards,

 

[B.G. Smith]

The 99 system compressor is cycled on and off by the switch located in the receiver/dryer. With your gages hooked up, what pressure do you show when compressor is off and when it cycles on. Compressor should cut off at 26/28 and come back on at around 46 pounds. Sounds like you are low on refrigerant???? bg

 

[gtwitch]

I have a similar problem which I intend to start on later today! My pressures are OK on the low side, but the high side is going out of sight to over 250 psi and the compressor shuts down on the high side switch. I am suspecting the expansion orfice!! How do i get that pulled out?? I have read that it takes a special tool?? Any suggestions??



gtwitch in wyoming

 

[B.G. Smith]

Are you getting good air flow through the condenser/radiator? Is the engine cooling fan operating correctly? Has refrigerant been added to the system? Does it cool at all? I believe the orifice is in the fiitting where the line hooks up to the condenser going to the evaporator, at right front of radiator area. Of course the system would have to be evacuated to replace the tube. Unless there is restricted air flow or too much refrigerant in the system the pressure should not be that high even with the orifice tube plugged unless there is air in the system. bg

 

[gtwitch]

I did evac the system and put the correct amount of R134 in the system and the system will cool at idle but when you get to highway speed ie 1900 rpm the guage pres on the high side goes out the top and high side switch shuts the compressor down and as the pressure equalises the system will short cycle again. That is why I think there is a restrictiion either in the filter drier or the expansion orfice. The filter drier is on the low side and there is no indication that the low side switch is shutting the system down. I am also going to fill the system this time with ES 12 refrigerant ( 6 oz = 16 oz of r134 or r12 and works with either PAG or the estr oil that the R12 systems use) and much larger molecules and lower working pressure. I just did my 96 dodge caravan and it cools like never before!! ES 12 is EnviroSafe 12 and is relative cheap and works great!! Google it and check it out!!

 

[B.G. Smith]

Consider this, if the orifice or the receiver drier were plugged/no flow the compressor would compress all the gas available to it to a pressure/temperature where it turns back to a liquid, with no more gas to work with the high pressure side should not go higher than the condensing pressure/temperature of the gas in the system unless the condenser were full of liquid which it should not be, maybe four or five coils in the bottom. ??? Maybe you have air in the system? bg

 

[gtwitch]

Food for thought!! My train on thought was that the only thing between the condensor and the evaporator was the expansion device (orfice tube in this case) and if the evaporator is not restricted and the filter drier is not an issue ( ie the low side is not dropping) this led me in my, train of thought, to the expansiion device! I just called the parts house and on the 99, the expansion tube is built into the liquid tube from the condensor to the evaporator ($47. 00) I think I will do a little more thinking!! I will keep the post informed.



gtwitch in wyoming

 

[HHhuntitall]

FIRST, I would start with a good bath of the condensor, intercooler, and radiator. Every spring I fix several that just need a good cleaning. Occasionally, I have to replace the fan clutch. It's not hard for a 134 system to go up to 250psi if the condensor has no air flow. Also, while you're working on it and have the guages hooked up, run some water or place a fan on high in front of the condensor and see if that keeps the head pressure down. If it does act normal, the problem is in your air flow through the condensor. IF it doesn't, you've got a restriction problem inline. I know on several I've pulled apart, the orifice is in the tube just out of the condensor, below the connector. It can be reached, on those, with a pair of needle-nose pliers, and removed. I have heard that some are made into the line. A standard filter/orifice replaces the ones I've seen, or it can usually just be cleaned. I've not seen many problems there, but have seen one that was basically welded shut from getting so hot... .

 

[gtwitch]

As I write this my system is pumping down with a good vac pump and will pump for 3 hrs and will replace the r134 with es 12 and we will see if I need to replace any other parts. . I did find the orifice is in the liquid tube from the condenser to the evaporator just ahead of the air box and is replaced as the whole unit (liquid tube) $47 at NAPA I thought I would just evac and recharge to see if there is a condenser air flow problem first or a blockage in the system somewhere else, I can reclaim and recharge if necessary if there is another probleml. I will let the post know! Thanks to all who chimed in!!!!



gtwitch in wyoming

 

[B.G. Smith]

When you break the vaccum just be sure you do it with refrigerant, it easy to get air in the systemtem when you switch from vacuum to charge mode. bg

 

[gtwitch]

Yes, I will bleed the refrig to the guage before I open it into the system. do you have another way that I am not aware of?? Always ready to learn a new twist if there is one, never to old to listen and learn!!!!

 

[Spunkys Ram]

Interested to know how it works out for you. I'm having some AC issues currently.

 

[BDaugherty]

Are you losing power to the compressor clutch after 30 seconds? A lot of times when a clutch gets pretty worn, it will pull in the first or second time, but not have enough power to pull in when it warms up. If that's the case, then you just need to remove a shim or replace the clutch.

Or, if you are hitting a safety switch, then that's a different problem. What do your pressures do when you turn it on?

 

[jmos4]

Hi all guess I am not the only one with AC issues



mine does have a full system and have changed both the High PSI and lOw PSI switches yet the high PSI will only go to 150 and the low is in the 40-60 psi



no leaks and the liquid tube gets cold at one end and slightly warmer at the other



the compressor works for a bout 30 seconds and shuts of and goes back and forth while running, believe if I could get the compressor to run longer it would get cold as the tube going to the EVAP does get cold



I took it in so will see what they have to say



thanks

 

[gtwitch]

jmos4 did you put a set of guages on the system?? what was the high side wdhen system cycles off?? As B. G. Smith suggested, before investing in a expansion orfice tube, I evac'ed my system for 4 plus hours and charged it with the correct amount of refrig and good to go. that was 2000 moles ago and still cooling better than ever has worked. Must have had some non-condensibles in the system that came out with the long evac process. I have done refrige systems for years and sometimes I put my head (well you know where) and get in a hurry! Thanks B. G.



gtwitch in wyoming

 

[jmos4]

Hi all,

I broke down and took it in to a repair facility, ended up being the Fluid Tube/Orifice tube was plugged as when they evacuated the system and went to take the line off it blew out a bunch of die and oil since its been replaced it works fine

 

[madmanmanick]

Ok, there are a few things that all of you might want to check and look at.



The system pressure for the system should be as follows: 32-40 psi low side, 190-220 psi high side, 8. 10 oz of refrigerant oil, and 2. 0 pounds of refrigerant.



1. gtwitch: you possibly have air and nons in the system. Evacuate the system as planned and put the correct amount of refrigerant and a can of refrigerant oil in the system. That is the reason the system is operating so high of pressure. Also, DO NOT!!! put R-12 in the system, I know you think that a certain amount of refrigerant will be equal to the amount of R-134a you are supposed to have, but it is more complicated than that. The chemical properties between the 2 is one thing. The other is the boiling and condensing pressures of the 2 refrigerants is to big of an extreme. Also the systems require different types of oil. If you do not put the correct type of refrigerant oil into the system the seals in the system will deteriorate and the systems will leak, and/or you will have to replace the compressor.



2. BDaugherty: your system may not have enough charge to be operate properly. 40-60 psi on the low side is a bit high, but it sounds like the system is not staying on long enough for the system to draw the low side down into pressure so the low side is still at the pressure when the clutch is disengaged and the high and low side equalize.



3. Jmos4: you may have a leak int eh system from when you replaced the switches and it is not allowing the system to operate properly. If not that you do not have the correct amount of refrigerant. evacuate the system and add refrigerant into the system until it stays running. while adding refrigerant the system pressure will go up and be quite high on the low side, when you close the valve on the manifold or the bottle the pressure will drop as the compressor takes suction. Add enough refrigerant to keep the system operating at normal pressure on the suction side, or if you use a scale to the correct amount of refrigerant.



4. To Everyone: after evacuating the system keep it under a vacuum until you are ready to put refrigerant back into the system. Then be very careful and ensure that you break it with refrigerant vapor, and not liquid. If you charge it with liquid the refrigerant will flash off as soon as it gets into the system and it will possibly crack piping or parts. To do this holding the refrigerant can hold it upright. After the system indicates pressure on the low side then you can start to charge it with liquid refrigerant (invert can).



Hope this helps you guys figure out the problems.

 

[truckerdesiree]

I have a 2000 Dodge 2500 with 283,000 miles and was recently that told that the reason my A/C suddenly stopped working despite refrigerant is being full and compressor working is because it needs orifice tube replaced probably. I am trying to find someone reputable in Las Vegas who I can take it to because I am not able to do it myself. I am about to make a trip to florida in it pulling a 5th wheel and really want to get it fixed before I head east. Would appreciate some advice.



Thanks,

Desiree

 

[B.G. Smith]

Yeah, you will most likely need the AC on your trip. We ran the AC in the house here a few days ago but it's supposed to be 30 here tonight. Could be the tube but kinda unusual for it to plug suddenly unless the compressor is shedding debris into the system. Best bet is if you can find a shop you can trust, have it checked out, they can hook up gages to the system and tell if the compressor is actually working or not. Several members live in that area and at Henderson, maybe some of them will chime in with some recommendations. Good luck. bg

 

[gtwitch]

Truckerdesiree, My son worked for " Auto Air and More" They are a great A/C shop and treat you fair!! Last name here is Twitchell and son's name is Dean, he is back in Wyoming and working in a shop here. Hope all turns out well!



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