chillin014

iTrader: (67)

I dont use my a/c much but it is summer and now it has crapped out on me. It was never much for consistency so I thought "low on refrigerant" well I did what any broke sob would do and picked up the crap at autozone with the little gauge. According to the gauge there was a satisfactory amount of refrigerant in the system already but I put a little more just in case (at least I think I did, the can actually seems faulty after checking on another vehicle).

To make a long story short, a few months later I try to use my A/C and the A/C compressor wont even turn on anymore and I have been told that could be due to all of the refrigerant leaking out. While it seems odd to me that it would ALL leak out suddenly, I am going through the procedure to check it all out. So far I have confirmed that it is not an electrical problem as I get power right at the compressor harness and a very low voltage at the signal wire, like .8 or .08, one of the two.

My question is, how do I jump the compressor to check the refrigerant level? It looks like its already getting the necessary power so...would hooking a battery up to the proper places really be any different? Maybe my compressor has just failed?

Either way...I am ready to fix this NOW. So any help is appreciated!!

modenaf1

iTrader: (3)

I can't speak from experience on the Maxima, but when my Taurus ran out of refrigerant in the system the compressor wouldn't turn on either. The gauge did read pressure in the low side line. So what I did was just keep filling the system with the can and eventually the compressor turned on, the pressure dropped and turned off in like 2 seconds. So I just kept at it and eventually the compressor turned on again for a bit longer, and two cans later it was good to go.

chillin014

iTrader: (67)

yeah i was getting no reading on the line closest to the passenger fender (is that the "high" side?) I wasnt aware you could even fill it up from the low-side. I wont attempt it though unless that turns out to be acceptable practice or something.

djipka

iTrader: (9)

low side it the one right next to the chain cover and pass fender. Working on the high side is DANGEROUS so don't do it at home.
Low and High stand for the pressure. The Haynes manual also says to fill from the LOW side. and there are instructions on the can when you buy it.

pmohr

iTrader: (26)

Do you mean jumping the pressure switch so it'll engage the compressor even if there isn't enough refrigerant?

Basically if you just jump pin 1 to pin 4 at the connector for the triple pressure switch, it'll 'think' there's just enough refrigerant in the system.

timmay5835

iTrader: (14)

Jump pins 87 and 30 on the A/C compressor clutch relay, that should turn your compressor on and will tell you if your compressor clutch if bad or if the control circuit is bad on the relay. Good luck.

Quickywd01

iTrader: (16)

Hook up the can, guage, and hose to the low side. You can try releasing the valve and see if a/c takes the charge, if not then jump the compressor like pmorh said and open up the valve on the can to let it into the system. The engine will need to be running so be careful. Have you read any of the instructions on how to do this? You could get hurt/killed if you just go pluging stuff into any port you see. Try the 134a+ cans with the plus sign. It gets really cold. The a/c in my maxima works great and I haven't touched it since I bought it 6 months ago. I did it this way on a '97 and '94 escort. Both were so low that I had to jump the compressor. The old escort held the charge after a few days/cans while the newer one leaked over the next few days and never held because the owner never used the a/c and the seals in the a/c system cracked from non-lubrication. Good luck.

chillin014

iTrader: (67)

I suppose so. Can you confirm what Timmay said about jumping it at the relay? Thats such an easier area to get to. Although I'm not sure which pins are which, hopefully the fsm has them numbered, dont remember seeing any in the relay box.

and I have been adding to the LOW SIDE, I just forgot that it was called that. I read the can's instructions before delving in, it was awhile back though.

I have already tried to add and it would not take any refrigerant. The valve on the can itself may be bad though as I said before, I will buy a new one but I know for a fact the gauge reads zero since I used an extra one they had at Autozone.

I also want to add that...I have a remote mounted IACV that was leaning against the low-side hose and it actually wore a groove into the aluminum a/c line. It didnt penetrate the line but I'm keeping that in mind in case the vibration may have caused damage further down the line where it connects to whatever is in the car at that point (evaporator core?) I have since isolated the two components with a piece of rubber. I just really dont see why all the sudden I would lose all of my refrigerant. I never had a problem before aside from the lack of consistent cooling on hot days.

thanks everyone!

max ride 41

iTrader: (4)

you can also add too much refridgerant and cause it to not work, thus have it done and they can flush w/ever's left and add the proper amount to the system. i would go that route if i were you.

chillin014

iTrader: (67)

I see, I see. While it is appealing to let a professional handle it and take care of it, I am super anti-mechanic since I do all of my own work. I'll at least diagnose it myself since it seems fairly easily. I'm betting that something is either up with the refrigerant or the a/c compressor took a crap. Once I determine if there is refrigerant in the system I will definitely consider taking it somewhere to have it professionally filled though.

I just really really want to get this fixed asap.

oldngivout

iTrader: (8)

There is one aspect of this system that you are ignoring though, that being the possibility that the compressor has the dreaded internal leak which spells death for the high mileage compressor. In order to diagnose this properly, you must monitor both the HIGH & LOW side pressure while the AC is running. The low side pressure in this case will abnormally high, like 50-80 psi.
Even if the system is properly charged, even if the compressor clutch is engaging, this condition will not produce cold air from the vents.

I understand your contempt for automotive repair professionals, but their tools & expertise do account for something. Repair on the AC system of modern cars is much more involved than adding a can of refrigerant from Autozone.

chillin014

iTrader: (67)

Well I dont think I am necessarily "ignoring" any aspect of it. Whatever is wrong with it, is wrong with it. I will replace the necessary components and bring it to a professional for re-filling if I feel necessary. There is no reason I can't diagnose this at MY shop before I just helplessly hand it over only to take someone-else's word for what was done as I foot an expensive bill. No disrespect intended, but I can make my own decisions about repairing my vehicle.

Now to get back on topic, can anyone confirm exactly which pins I should be jumping at the relay? It sounds like the pressure on the low-side alone will tell me a lot about what is going on.

timmay5835

iTrader: (14)

Try to get your hands on a manifold guage set to see your pressures while the A/C is running. And look on the back of the relay, the pins are numbered there.

chillin014

iTrader: (67)

ahh i will check that. Your saying just put a wire to bridge those two connections, right?

gotta get the a/c running before i can use a gauge.

oldngivout

iTrader: (8)

Ok, fine, so you are not ignoring the possibility of the internally leaking compressor. You just were not aware of it. I have replaced several of them due to that condition. Just trying to help.

The static charge in the system should be 70-90 psi. This is where a set of gages would come in handy. All you have to do to get the compressor clutch to engage, is to run a jumper wire from the 12v+ battery terminal to the compressor. Well, that's one way to do it.

Oh, and if the compressor engages and the system runs, the LOW side pressure reading will still not accurately reflect the mount of refrigerant in the system. That can only be verified by removing & measuring it, or by installing a known amount when refilling after evacuation.

chillin014

iTrader: (67)

lol sorry, I appreciate the help! I'd almost prefer that the compressor be bad so I can just replace it and be done with all of this.

The only gauge I have to go by is this cheap autozone can-gauge POS. Maybe I should buy a set if they arent too expensive, this isnt likely to be the only car I have to mess with.

I dont know how I feel about trying to hook up a 12v in that cramped area where the compressor is. Plus, it seems like its already getting power...so I'll try to relay first and report back soon here

max ride 41

iTrader: (4)

seriously tho, i had it done and when they refill the system they add something to the compressor which lubes it up inside so you dont have it seizing or not working at all. my guy did it for a fin plus tax??!!?! took him an hour and it blows cold as $hit now.

chillin014

iTrader: (67)

I checked under the relay and the pins were numbered like....1,3,4,5 or something along those lines. no 87 or 30 .

Ah, I'm an idiot. I can see on top of the relay where it shows the ciricuit schematics of the pins. 3 to 5 is a "switch" and 1 and 2 have the little coil I'm guessing means "fixed" or always connected. So in that case I would just be connecting 3 to 5 and 1 to 2 and I'd be "jumping" it, right? Is this any different than doing it right at the compressor itself?

chillin014

iTrader: (67)

Okay so I made the proper connections and the a/c compressor turned right on! I still dont know if this confirms that the a/c compressor is not at fault for the problem but the gauge was not reading anything on the low-side. I bought a new bottle of the refrigerant so I am going to see if I can get anything in there... I'd hate to have a big leak and take it to someone only to have all of it seep out immediately.

chillin014

iTrader: (67)

More good news (sorta). I put the refrigerant in. Somehow a 17oz bottle filled it up to where the low side reads "55 psi" which is supposedly the Max for the system, I thought it would take more. Anyways, with refrigerant in the system the A/C compressor comes on perfectly fine by itself now. The A/C wasnt blowing very cold in the garage but the whole car was heat soaked so I'm going to take it for a drive in awhile and see how well it performs. I remember it being MUCH colder when air was being pushed through the condenser. I do believe the system should work better than that however at least now that I know it is the problem I can take it to someone who can fill it properly with the good stuff.

I wish I knew how it had leaked out though. I'll figure it out one way or the other though.

Mad Medicine

a/c specialist have stuff that they can inject into the system to find leaks. Its like a fluorescent color. You might be able to find this stuff somewhere. Also from what i remember is this stuff stains clothes easily

But it's like someone mention here, its best to bring your car in to check what's wrong with the a/c.

chillin014

iTrader: (67)

They actually sell the dye at the auto store, I am completely familiar with the whole concept. I am capable of determining what is "best" for me and my car though, thank you.

njmaxseltd

iTrader: (19)

Thats way to high! R134 low side should be around 27 - 35 PSI depending on ambient temp. At 55 PSI you are way overfilled which is why your not blowing cold A/C.

chillin014

iTrader: (67)

oh yeah? Damnit, I was going off of the stupid chart on the can. I will mess with it

maximalstealth

Some things that you may not be aware of : Adding refrigerant into the low side if you were out of refrigerant the system may of induced air which contains moisture this is why the system is evacuated. and the system in put in a deep vacuum and moisture reaches its boiling point and is removed as a gas. if the system does not hold a vacuum then a leak is suspect. diagnosing a system requires gauges to monitor both the discharge and suction sides of the system. the proper charge is done by weight and normally the system holds only is a few oz. improper or an overcharge on a hot day will cause an internal relief valve to release, if the relief valve fails the discharge of the compressor will be high enough to seize the compressor while the belts continue to run and squeal. if the clutch engages then the compressor is working, the system has a low pressure switch should the pressure fall below the factory fixed setting this switch opens the circuit to the compressor clutch. if your system has a leak the most suspected area would be the condenser which is in front of the radiator due to rock damage. this would be on the high side or discharge and would rapidly loose charge.

chillin014

iTrader: (67)

As an update or sort-of "conclusion" I let a local mechanic do a leak test and he said the compressor itself is shot and that is where the leaking is occurring. He said it makes all kinds of noise and **** which I probably assumed to be normal. I hope he's right because Ive got no way to prove him otherwise and I'm about to drop a billion dollars on these parts.

L0R1DA

From what I gather, you likely overfilled the system which reduced the evaporator's capacity to evaporate the refrigerant, which means your compressor tried to compress a liquid (something a liquid cannot do). Don't feel too bad because if you had the original compressor still, it would probably make sense to change it after all this time anyway. Just be aware if there is a leak somewhere else in the system such as in the condenser or evaporator or either of the service port valves (most common) the new compressor won't last very long. The way to test this is to connect the refrigerant recovery machine (I assume your mechanic has this, otherwise he cannot legally perform your repair) and run a vacuum on the system and then let it sit for about 20-30 minutes and watch the reading to see if the system holds vacuum, if not, you still have a leak.

I hope your mechanic at least used a manifold gauge set on the system before proclaiming that your compressor is f---ed. Noises can be an indication of malfunction but you need to look at the pressures to diagnose correctly. Also if your system is leaking it is pretty messed up to just top it off with more refrigerant so it can leak back out... I don't know why those crap Autozone cans are still legal for the public to buy after all the noise they made about r-12... Also it is perfectly fine to inject refrigerant into the low side of the system, just don't ever try injecting it into the high side with the engine running! High side is the thin diameter tubing and low side is the wider diameter tubing. Good luck!

chillin014

iTrader: (67)

Well, I didn't really expect the autozone refrigerant to solve my problem, I just wanted to make sure my A/C compressor still worked or that the problem wasn't elsewhere since there was nothing in the system to begin with (for whatever reason). Unfortunately it works, just very crappily. But like you said, it is the original, and has 180k on it, so it's no surprise.

The mechanic did do a pressure test with the proper machinery. I am not exactly sure how he confirmed that the compressor was what was leaking but he said something about the "head" not even being able to hold pressure. I am about to go pick the car up and find out what else he was saying to replace besides the expansion valve, I hope it wasn't the condensor...that's another 100+ right there.

chillin014

iTrader: (67)

I just got the car back. He said to replace the compressor, drier, and possibly the expansion valve. Drier's are dirt cheap so that's no problem. Now i just need to find out exactly which a/c compressor I need. I dont understand the differences between them but I know you have to buy based on your manuf. date or something.