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General Forums => The Mess Hall => Topic started by: Jeffy on July 23, 2005, 01:20:21 AM
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Well the A/C unit in a non-Jeep has been out for a while. The owner didn't get ti fixed while under warranty and now that Dealer is gone. (ie., closed down.) It seems the compressor is not turning on. The owner said the Dealer checked the pressure and it was fine. They wanted to replace the pump and that wasn't going to happen. So is there wany way I can check the pressure with an air gauge or do I need a special one. (I've got a digital gauge.) I've been told to bypass the HI and LO pressure switches to see if that does anything. There can't be that much to the system that can go wrong if there is no leak. Although it would be nice to confirm the pressure without buying anything. The owner wanted to just get the system topped off again. Seems that sorta helps but I think the problem should be fixed rather then spend money to recharge the system every summer.
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No one has A/C I guess...
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Well, there might be someone who is interested in A/C.
So here's the outcome. I jumped the low-pressure switch with a paperclip and the compressor worked. Still blowing hot. So that means the system is low on R-134a. If it was the switch, and there was enough R-134a in there it should have worked.
So thins being mid-summer recharge kits of slim pickings. Went to K-Mart, AutoZone, Pep-Boys and Kragen. Prices vary depending on the kits. There seems to be two different can types. One uses a setup that white gas uses. Screw on the tap then it punctures the top and locks on. The other type seems to be more like a standard arisol canister.
I went with a gauge and hose setup that screwed onto the top so it is reusable. The recharge cans seem to be easier to find then the other type. I also noticed that not all of the kits come with gauges. Some of the really small top-off canister's dont have them.
Also, if you're going to recharge the system, make sure you know how much refrigerant to buy. The system I'm working on is 1.85lbs. I bought a 10oz and a 10oz can. I've still got to recharge the system. It's been in the 100's for the past two weeks so I'm not looking forward to standing outside and working on it. I'll probably get to it tomorrow.
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I did this on my S10 about 2 weeks ago. Took me all of about 10 minutes to add refrigerant and finally I have A/C again!!! I also chose the can with the hose and gauge attached.
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Well it was down to 10 psi or somthing. I dumped most of a 19oz can into the system and got it up to 40psi. The compressor no longer needs to be bypassed to run. It's blowing cool air but it's not super cold. I'm not sure if that's because it's over 100 outside or the system didn't get charged right.
The can said to keep it upright and shake occasionally. Some people say you can pour in liquid R-134a but no more then a can worth. The can I got is 19oz, so that would be a heck of a lot.
I think I might ahve to take it for a trip to see if it gets cooler. I think I also found the leak. It's at the low-pressure fill port. It leaks out the cap! It doesn't leak if there is something connected to it! Tightened down the cap and hopefully it will hold pressure.
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I'm not sure if that's because it's over 100 outside or the system didn't get charged right.
I'm sure it's because of the heat. Me, and a lot of people I know, are having the same problem. I used to be able to leave my A/C (in the truck, not the Jeep) at 1 and "not so cold" setting a few months ago, now, depending on how long the truck's been sitting outside, I need 2 at the coldest setting and it still feels hot.
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I went out in the heat. The temp from the vent was around 80* when it was 100* outside. Parked at the Mall and went shopping. By the time I got back the temp inside was around 111*. A/C turned on and that dropped to 80*. That was with the A/C on Max and the fan set to one below Max. When the temp dropped to 95* I lowered the A/C to regular and the temp dropped to 70-75*. It still seems a bit warm though. I would have liked to have it feel like a cool glass of ice water. At least it's working. I can now drive it with the windows closed.
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Whats AC?
Do you really drive a jeep :P
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Jeffy:
I just bought a 97 TJ and have been experiencing some AC concerns, on my jeep, the AC works fine up until the engine warms up to operating temperture then it starts blowing warm air. When the engine cools just a few degrees, it works then blows warm air when it again reaches operating temp. I've re-charged the system, but it didn't help. Any ideas on what I could check next? :(
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I'd maybe disconnect the low-pressure switch and jump the terminals in the plug. This will allow the AC Compressor to turn on without any bearing on the pressure. I'd start there first.
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Jeffy:
Thanks for the advice, I'll give it a shot this weekend. Let you know the outcome, :D
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Jeffy:
Before I dive into my jeep and begin pulling wires, where is the low-pressure switch located? Is there any special way I should jump the wires?
Thanks,
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Well, that will depend. Sometimes it's on the Condensor. If it's on the condensor then it's easy to unplug and get to.
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ok the low pressure swicth is on the accumulator/dryer the "condensor" is the small radiator thats attached to your engine radiator ........95% of chysler a/c problems are the evaporator located under the dash ,they get small leaks and internal rescritions causing poor performance in your a/c system .you may get lucky and find small leak in hose or cap and you may have to replace your core's (located were you hook up the guage ) but the real fix is replacing the evaporator under the dash ...it will cost just about as much as new compressor or maybe more depending on where you go ...best advice .........when the evaporater goes take the top off jeep and convert your a/c compressor to a air compressor so you can fill tires and use air tools when out WHEELIN ...........lol
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Well, this was a '96/7 Blazer. The port on the dryer leaks. It does not leak with a gauge on there.
But when filled, the A/C would blow barely cold. I think it might be the orifice tube/expansion valve.
Oh and this isn't on a Jeep. So when the temps hit three digits, it gets pretty warm inside.
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A/C systems need to run at a certain charge/pressure . It cant be too high or too low or the performance will suffer. and depending on the system any of the compontes could be the cause ive seen clogged condensors externally(with bugs and dirt ) and internally (possible pinch or dent in lines) evaps do have a nasty habit of small leaks along with the possibility of clogged orifice tube /exspansion valve. you can get away with not bleeding the whole system down and weighing the charge with a set of a/c gauges and little by little adding a small amount of refrigerant untill you get aprox 28-30psi while the vehicle is running compressor on idled up to about 2000rpm at the same time after each addition of r-134a give it time to equal out in the system and check the temp comeing out of the vents keep this up until you have the desired temp or the temp starts to rise in whick case you've gone too far there are other issues with the clogged orifice that can also arise but this has always been a good starting point
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oh and those valves you say are leaking can be replaced they are basically the same type as a tire valve stem but a diff size .. you should be able to get them at a auto parts store
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My uncle and I use the Interdynamics recharge kit pictured below to do A/C work. He's a dealership service manager and been doing this stuff for a living for 30 years. He's even got the "sniffer" probe to detect leaks- über cool! It costs less than $20 and works well. Best of all, it keeps you from overcharging.
I had the low-pressure switch blow on my Jeep this past summer about a month after I had a shop install a new compressor; the old one died. Of course, I then promptly moved back to VA! The good news is that my uncle helped teach me A/C and we solved it with a new switch and a couple cans of R-134a.
Since it doesn't sound like the Chevy's system has been opened to the atmosphere and merely lost refrigerant instead, you should only need to add refrigerant. Be careful of using the oil/refrigerant mixes too often. You can get too much oil in the system. The other thing to be careful of is overcharging. If you overpressurize the system, it won't cool properly since there's too much overall pressure in the system to allow for proper expansion; it's the expansion at the orifice tube that provides the cooling.
Good luck! Even if it is still winter... :wink:
Interdynamics EZ Chill Quick Charge R-134a Charging & Measuring Kit
http://www.id-usa.com/product.asp?CID=27&PID=45
(http://www.id-usa.com/images/full/prod_45_ful_QC-1CS.jpg)
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hey thats nifty i havent seen those :D
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Well, I like I said, it doesn't blow cold. The switch low-pressure switch isn't bad since I can bypass it and turn the compressor on. When full the system does work but isn't that cold. I still think it's the expansion valve. I've already got a gauge/filler.
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thats the most common and easy to replace .. unless you have somthing to recover the 134 you'll have to get new stuff .. maybe check to see what the charge weight is for that vehicle and go by that instead of pressure ... just my 2 cents :)
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thats the most common and easy to replace .. unless you have somthing to recover the 134 you'll have to get new stuff .. maybe check to see what the charge weight is for that vehicle and go by that instead of pressure ... just my 2 cents :)
Hahah, that's not a problem. it all leaked out of the dryer in a few weeks. Can the expansion valce be cleaned? I'd assuming since the system was dry for an extended period of time any coolant or oil might have dried on the screen. I'll probably have to replace the dryer too.
Stupid thing is this all started because the Dealer replaced the radiator once and had to drain and refill the system. Then my parents didn't take it back and complain even when I told them to 3 months after the work was done and the AC leaked out. It's been a few years now. What a PITA.
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guess you could clean it but i dont think they are more then a few bucks .. if the dryer has been exposed to air/moisture it too "should" be replaced but ive gotten away without doing so, but if it's leaking then thats another problem :( and if it's all drained anyway change out that schrader valve on the inlet and try to get a vaccum on the system before charging again
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Never priced one but if it's cheap then it would be better to just replace it. How much would it cost to vacuum it? For that matter a recharge? If it's under $30 then it's not a big deal.
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if you know someone with a pump ... a shop will charge time+134 most ive seen per # is $9 then 1/2 hr shop rate is what we would charge looking more around $60 for this area but im in CT :(
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How crucial is it to get all the air out? Can it be done without the pump?
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if your having performance issues anway i would say you would want to get some vac on it before recharge some systems are more touchy about this then others... i was talking to a friend of mine about this thread and he had told me he used a pump out of an old fridge.. he McGyvered it together and it still works fine for him lol
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yes you do want to vacuum system .jc witney has cheap vacuums and for automotive its worth having one .....you want no atmosphere in your system if you want it to last .........yes dryer should be replaced if opening system .....yes orifice can be blown out best to use dry nitrogen .....in fact you should blow out all lines with nitro if possible once sytem is reassembled charge sytem with 50lbs dry nitro leave overnight and see if you still have leaks.then pull deep vacuum.....time is not most important .to see if you have moisture in system (killer on compressor and freezes orifice) pull vacuum 15 min drain oil from vac put in clear glass .is it cloudy? if yes put new oil in vac and pull down another 15 min ...still cloudy ? keep repeading if by the fourth or 5th vacuum still cloudy you have leak or there is major water in system witch will cause ac to not blow cold even if fully charged ...once you have all moisture removed .the proper way to charge a ac system is by manufacuer specs IE: THIS A/C UNIT HOLDS 3.78 OUNCES you can use a digital scale or if you can find one a dial a charge..but remember to account for hose lenght.there is alot to an a/c system sometimes its worth the 100 to 200 dollars to fix :shock: