96 Geo AC has stopped working but everything else OK

[geoshuttle]

My GEO has run without any problems since I bought it in 97, I love that car. Poeple make fun of it but I don't care, it's my reliable little shuttle. It has nearly 80k on it now and I have taken very good care of it.

Recently however the AC has been fading. Over the past couple of months it has stopped working all together with intermittant episodes where it seems to have healed itself and worked for a trip or two. But now I think it has died for good, I press the AC button and the air doesn't get cold. I do hear a slight familiar "AC Noise" from under the hood, but it doesn't sound like it stays on as the car resumes "normal" running sounds. If I recall correctly I could always hear when the AC was on by the sound the engine running would make. A few weeks ago was the last time it actually worked and now it won't budge at all. I also always knew when the AC is turned on because there's a noticeable dip in accelleration power but nothing I havent learned how to compensate for over the years with my driving habits (I have an automatic so I just turn it on when fully accellerated). The acceleration drain doesnt seem to happen now-- The AC is on but even while driving the car doesn't do it's familiar "power dip".

I took the car to a pep boys today for an AC check. They put a dye in the compressor to check for leaks and say they don't see any but to come back in a couple of days (that for $30). They also said they bypassed the AC by connecting it to the battery directly and that that made the compressor (AC) turn on, so they they say the problem must be electrical. I didn't witness any of this so I dont know if it actually happened. They told me it would take an hour and 4 hours later they finally got around to doing the test then rushed me out the door with the above explanation and citing I'd need to next to a $73 electrical systems test to possibly find the cause of why the AC compressor isn't powering up, so I'm a bit skeptical of their competence. I have a deep mistrust of any auto repair shop so I was just wondering if any of you out there have had similar experiences with your GEO air conditioners and what fixed it?? Any insights or anecdotal info would be highly appreciated!

Lermanuel Dias

[geoshuttle]

Well going to Pep boys was a major mistake, I've never experiences such incompetance in my life. I returned today as they instructed to and no one there remembered me and they sent me away to an electronics specialist who of course couldnt help me either. He took a look and fiddled with some things but said he's not experienced enough with suzukis (the make of GEO under to hood) to know to fix it.

He said it's most likely a problem with a relay or a couple of other things I cant even remember right now (something about an accelerator? or an evaporator). He did do one test were he bypassed this relay and that made the AC kick on, but the relay wasn't bad he said, which I dont understand.

I was really hoping to have this fixed while I was up in town visiting my mom, but Friday I have to return to the big city and things there are always more expensive and more of a hassel to arrange.

[geojim]

Did Pep Boys, or your mechanic, check the pressure in the A/C to see if you have sufficient refrigerant in the system? If the R-134a/R-12 drops below a certain level, the compressor is cut-off electrically by design

[Zogboy]

get a r134 hose kit for a couple of buck and a can of 134a freon .
follow the direction on the kit. If you a/c works after that stop worring about it.
Sometimes the clutch can wear out but it is probably just low freon pressure.

[geoshuttle]

Originally Posted by geojim

Did Pep Boys, or your mechanic, check the pressure in the A/C to see if you have sufficient refrigerant in the system? If the R-134a/R-12 drops below a certain level, the compressor is cut-off electrically by design

Thanks for your reply! As far as I know the only thing Pep Boys did was put an ultraviolet dye in the compressor to check for leaks, which they couldn't find. Since they coudlnt get it to turn on other than by connecting it directly to the battery (which led them to their electronics problem diagnosis), I really dont know how they could have found a leak.

I do think you're right about the pressure, it was one of the things the other AC guy I talked to mentioned it could be. He did check it and said it was "low" but not "super low" and that it could just be lower because it was cold out. Since he wasn't familiar with the GEO maybe he didnt know that low pressure would cause the system to automatically bypass the switch and not allow the AC to turn on at all (is this unique to GEO ?)

Here's a catch, as I mentioned earlier the problem had been intermittant, I had thought it had "finally given up for good" this weekend since I was trying to to turn it on more than usual as it's warmer down in the CA valley, but, today out of nowhere the AC started working again, and the only thing different about today and the rest of the days it didnt work, is today it is about to rain so I imagine the barometric pressure is lowerering, so I imagine whatever freon sensor in the car now is just above a certain level so it lets the compressor turn on.

From what I'm remembering now, the last times it did work over the past few times were on days when we had low pressure fronts, which in the Bay Area of CA usually just means cooler weather. When it would get hot (when I actually needed it) it wouldnt turn on.


Does this sound plausible to you? Given that it does turn on I would guess it' probably not a broken electronics thing, but a correct sensor reading and something to do with pressure and how it reads the pressure dependant on the relative barometric pressure outside?

Thanks so much for your help!

[geoshuttle]

Originally Posted by Zogboy

get a r134 hose kit for a couple of buck and a can of 134a freon .
follow the direction on the kit. If you a/c works after that stop worring about it.
Sometimes the clutch can wear out but it is probably just low freon pressure.

I think I will indeed try that! I didnt know that there were do-it-yourself freon recharge kits out there. I always thought since it was such a toxic thing it was only for authorized mechanics.

If you see my reply above, I do also now believe it's pressure since today the AC miraculously turned on again and the only thing different is today the pressure outside is lower as we have a rain front on the way. I imagine lower barometric pressure outside means the pressure of the freon in the compressor rises above the few decimals points needed to alet the sensor to allow it to turn on when I press the button.

If it does indeed turn out to be that, I'm asking for my money back from Pep boys, as I think this should have been a relatively easy "by the book" diagnosis and fix wouldn't you agree?

[Crvett69]

before you just fill the system with R134 you have to have all the old r-12 sucked out and a vacuum reading in the system. you can't buy r-12 unless your a liscenced refrigeration person and its real expensive anyway. if you find the switch for your ac pressure (its usually by the dryer) the dryer is the round can looking thing usually close to radiator you can jump across it with a wire and see if ac comes on. if it does then you have a bad switch or low pressure. take it to a licenced ac place and have them suck out the old R-12. some will do it for free cause they can filter the old R-12 and sell it again. once all old stuff is sucked out you can buy the cans and gauge to refill it yourself, usually about $30 for stuff you need to refill it yourself but first you have to get old R-12 out since you can't mix R-12 and R134

[geojim]

Look under the hood for an A/C sticker which will indicate the type of refrigerant used; R-12 or R-134a. A '96 probably has R-134a in it, which makes it a lot easier.

[Zogboy]

the r12 connectors won't fit on 134a
and 134a is no as toxic as r12 was suppose to be, all of the cars after 93 or 94 use 134a
get the 134a with stop leak and oil in it if you can.
Do not put more than 1 can in your system and check the pressure......all this info is under your hood look for it

An a/c shop shouldn't charge more that 50 - 100 bucks to do this for you or buy the tool and freon for less than that and do it yourself

[geoshuttle]

Originally Posted by Zogboy

the r12 connectors won't fit on 134a
and 134a is no as toxic as r12 was suppose to be, all of the cars after 93 or 94 use 134a
get the 134a with stop leak and oil in it if you can.
Do not put more than 1 can in your system and check the pressure......all this info is under your hood look for it

An a/c shop shouldn't charge more that 50 - 100 bucks to do this for you or buy the tool and freon for less than that and do it yourself

Well I took it back to the pep boys from hell since i wanted a credit for my last visit and for them to do the recharge. 3 hours and $85 later they said they did the recharge of the freon. It is R134a. The AC was working when I took it there and I explained to them how it would work itermittingly and how it appeared to be related to the weather outside.

Well after they did the recharge (drain and then refill) I tried it again and it wouldnt kick on at all again. Coincidentialy (or maybe not) the sun came out and it starting to warm up outside. They didnt even test it after they did the recharge and no one explained anything to me. It's the worst customer service I've ever experienced--I think there will be some charge backs to my credit card and theyll have to deal with the hassel of contesting them.

Does anyone know what would be causing this behavior? What would make it kick on intermittingly? Could it be a bad sensor that's not reading the freon pressure correctly? What would be the most cost effective way of getting this fixed. Does anyone have any recommended mechanics places?

Thanks again for any advice anyone has to offer!

[JerryHughes]

Hi geoshuttle,

I'm just wondering if you ever found out what was wrong with your air conditioner? Same problem on this end. Any help is appreciated. Thanks,

Jerry

[Ge0Sc0ut]

Alright my A/C doesn't work at all and im really over it, cause it sounds like to me that you had your own hassle just to live comfortably in your Geo, I PERSONALLY HATE PEP BOYS WITH A PASSION, Cause they don't care its not there car.

My only suggestion is that you live without it or live with it while you have it sometimes hehehe confusing....Well I hope you get a good ansrew cause maybe i'll try it if its not too much trouble otherwise ill just live without AC which in California it kinda sucks not to have it.....

[chembrad]

FYI

R12 is dichlorodifluoromethane (CCl2F2)
R134a is 1,1,1,2-tetrafluroethane (F3C-CH2F)

There really isn't a whole lot of different in the toxicity of the two. Check out the MSDS for the compounds to see for yourself.

And regarding dumping all R12 before you add R134a seems pointless. I cannot see any chemical reason for doing so. These chemicals have similar properties and are mixable at all concentrations and both are practically inert.

[MrPink]

Since he has a '96, he doesn't have an R-12 system.

And you're correct, there's no real reason you can't mix the two in the system, except for possible oil incompatibilites (you'd want to use an ester-based oil, it's backwards and forwards compatible) and remotely possible receiver/drier issues.

But Federal law requires that all R-12 be recovered in the process of a retrofit, and it can only be done by someone with a certificate. Most shops will do an evac for free, since the R-12 is so valuable.

-Pink

[geoshuttle]

Originally Posted by Ge0Sc0ut

Alright my A/C doesn't work at all and im really over it, cause it sounds like to me that you had your own hassle just to live comfortably in your Geo, I PERSONALLY HATE PEP BOYS WITH A PASSION, Cause they don't care its not there car.

My only suggestion is that you live without it or live with it while you have it sometimes hehehe confusing....Well I hope you get a good ansrew cause maybe i'll try it if its not too much trouble otherwise ill just live without AC which in California it kinda sucks not to have it.....

I just wanted to let everyone know that I took my car to another mechanic that knows more about Geos and they found the problem in less than an hour. As suspected and as a few guys mentioned in this thread, it was a pressure problem and the electronics system automatically won't let the compressor kick on if the pressure goes below a certain point.

The reason for the pressure drop was a faulty <a href="http://autorepair.about.com/cs/generalinfo/l/bldef_724a.htm"> "schrader valve"</a>, it's a little valve like the ones you see on bike tires to let the air out. It costs about $2.50 . However, since it's a hassle to replace and since the AC needed to be drained to replace it, after all was said and done the job cost me $245.

I didn't actually mind so much the cost, I'm just so happy to have the AC working again especially now that the weather is warming up. Plus, I sorta consider it "free to me" since if you read my other thread <a href="http://www.automotiveforums.com/vbulletin/showthread.php?t=366261"> here </a> about my little rear ender, I received a settlement of $1250 from the SUV lady that hit me. Well the dented under body (jammed the spare tire so it couldn't be pulled out) only cost $400 to fix, so now with this $245, I still have $600 left over! I think I'm going to use that to paint the car...btw does anyone recommend any place in particular? Is Maaco good? I hear they could do the whole car for less than 600.... Anyway...

Alls well that ends well, but I'm just still pissed that pep boys was so incompetant that they didnt know about the pressure thing. In their defense the guy who found the problem said sometimes AC problems are difficult to diagnose, but to me this sounded like a pretty by the book problem, I guess though experience history does help...so do any other experts on here agree that the shrader valve was indeed the culprit? I've been using the AC for a few days now and so far it seems smooth sailing, it's even colder that it was before, just like when I first bought the car.

Thanks again to everyone who responded and helped!