posted by
someone claiming to be greg nottingham
on
Sat Jul 26 01:57 CST 2003 [ RELATED]
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I have had my 1994 940T for three years. I have never had the AC serviced as it has worked great until this year.
The cooling seemed to be operating intermittently and seems to have stopped now. The compressor won't start.
I have not put any guages on it yet, but if there is some refigerant left, but not enough to overcome the low pressure switch, is it acceptable to recharge with the compressor running or should I have the old refrigerant recovered, evacuate, and then refill with R-134a?
I have not noticed any oily residue around any of the external fittings, hoses, compressor, or condensor.
Thanks.
Greg Nottingham
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posted by
someone claiming to be 960Lover
on
Sat Jul 26 08:19 CST 2003 [ RELATED]
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Some time ago one of our "back yard mechanic types" posted a very detailed method for recharging the A/C system and I posted a very specfic warning that this is NO job for amateurs. Just because a job CAN be done by a home mechanic if ne gets lucky and everything goes right doesn't mean it should be tried.
You can literally blind or kill yourself if you hook up the refill can to the wrong port and a metal can explodes in your face (eyes) or cuts the artery in your neck.
As a professional ASE Certified technician, I am trained to do such things, but shade tree types typically screw things up, so I am telling you guys to stay away from dangerous systems where you can hurt yourself (like this) or your family by messing with stuff like throtle associated components, or brakes.
Just do yourself (and your family) a favor and leave it to the pros. It will be the cheapest $100 you ever spent.
It amazes me that people will spend $10 or $20 thousand for a car, then cheap out for a few hundred to make unsafe repairs.
How about you establish a rational value system for yourself, and let the experts do what they are trained to do.
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Funny you should spout off like that in a forum designed for us shade tree screw-ups. Many of us have had ample training, in various venues, some of us even have been the trainers, some of us evenknow what we are doing. Many of us work on our own vehicles because we know we can and have had poor results from the "pros". Admittedly, some have no business handling a screwdriver. Most of us are somewhere in between. The fact that greg is asking instead of blindly turning valves speaks to his competence, IMO, as far as safety is concerned. Your post (and my reply) is better off being placed in the "Opinions Forum".
That being said, I think greg should have a pro look at his system, this is why. Some Volvos do not have a high side Shrader valve tap so you cannot effectively measure system charge (one of those things Volvo did to keep us screw-ups from killing ourselves?). Charge is measured via how much refrigerant is put in the system after being evacuated. If the system is low on charge, it had to go somewhere which points to a leak which needs to be found and fixed, this is most easily done by a competent pro with all the right equipment. So, greg, you are right, it sounds like a low charge but there is a reason it is low which should be dealt with before you add a can of refrigerant in it.
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Bob Kraushaar '94 945T, '91 940T(back from retirement), '88 240, '84 242T, '94 F-150, '89 560 SL, '68 Shelby GT-500 KR
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posted by
someone claiming to be greg nottingham
on
Mon Jul 28 14:30 CST 2003 [ RELATED]
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Bob,
I was going to ignore the comments, but decided to respond since you took the time.
I guess I am in between. I appreciate 960lover's comments, because I know some people have really messed up, like the guy a year or so ago who jacked up his motor on the oil pan nut, dinged his oil pan and flamed Don Foster. AC work can be dangerous if you go blindly rushing in.
I've been doing the majority of the work on my vehicles for close to 30 years now. I do know the difference between the low and high pressure ports and do realize they are different sizes in most 134 systems, at least the ones I work on. I also am aware that there is only a low pressure port on the accumalator on my system. My Firebird and Grand Caravan are set up differently.
I always wear goggles and face shields when working around AC and wear gloves.
As far as venting to the atmosphere, the base will recover the refrigerant free of charge and they have charging stations at nominal cost. I have access to frame and drive on lifts too. The Auto Hobby Shop is a good deal.
I just paid over $813 total, $500 in labor, for AC work on the van because it went out the day before getting underway and I didn't have time to take it to the auto hobby shop. I'm sure the shop earned the money, but $500 in labor is a lot of money to me.
I also enjoy working on cars.
As far as spending 20K plus on vehicles, I bought the Volvo used for $9K, no way would I spend $20K or more on a Volvo or any other car, and no way could I afford for a shop to do all of my work on the car. I will be in the used car market for quite a while.
Looks like I have a clutch or MCC box issue like Brickbat mentions because I get 100psi at 88F at the accumalator and almost 12V at the compressor positive lead.
Thanks for taking the time to weigh in.
Greg
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'nuf said.
--
Bob Kraushaar '94 945T, '91 940T(back from retirement), '88 240, '84 242Ti, '94 F-150, '89 560 SL, '68 Shelby GT-500 KR
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posted by
someone claiming to be batbrick
on
Sat Jul 26 05:02 CST 2003 [ RELATED]
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I have 2 94 940 na's, and here is something you might want to check first... The A/C was working perfectly fine and then would only work sometimes, but when it did work, would work fine. It turned out to be a bad solder joint on the A/C control panel in the dashboard (a real pain to remove, btw...) The solder joint on the relay that sends power to the compressor had cracked, so I was getting 12V to the compressor, but there was not enough CURRENT to the compressor to get the compressor to turn on. This happened on both of my 940's within the past 6 months. I hope this helps.
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Great info. This seems to be exactly what goes on with my '94 940 wagon and in Phoenix, AZ I can't afford to do without the AC. I recently had the AC recharged and when it is working it blows very cold. But it decides to go on hiatus every once in a while. My question is where will I find the AC controller panel to look for the possible cracked solder joint? Or where I can I find a diagram of the what is beneath my dash.
PS. I am a newbie to volvos but mechanically inclined...
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I saw your post and thought to myself "this sounds so common, it should be in the FAQ." I just checked the 700/900 FAQ, and this exact problem is there. That would have saved me some time the first time... Anyway, go to Features --> 700/900 FAQ --> Heating and Air Conditioning --> MCC Climate Control A/C Not Working. That explains the problem way better than I can! Hope that helps.
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posted by
someone claiming to be greg nottingham
on
Mon Jul 28 14:11 CST 2003 [ RELATED]
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Batbrick,
What troubleshooting steps did you use to arrive at a bad MCC and not a clutch? I assume you have a MCC.
I put the guages on and it read 100 psi at the accumalator. I also get 11.71VDC at the compressor lead on the engine side of the connector.
Either way, it looks tough. If it is a MCC, I have to take part of the dash apart. This will be time consuming and may be a tough soldering job like you said. If it is a bad clutch, I've always been told that it is cheaper and simpler to just replace the whole compressor.
Apparently there is still plenty of charge as evidenced by 100psi at 88F or so. Also, when the A/C was working, I almost froze. My problem sounds identical to yours, I'm just not sure of the root cause.
Any leads would be appreciated.
Thanks,
Greg
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Greg,
I do have the manual climate control with the 3 dials. I first checked for leaks using a UV light that will highlight the A/C dye that I made sure the last shop that charged the A/C system put in. Since there were no apparent leaks, and it worked great (sometimes), I was pretty sure that the compressor and clutch were fine, and that there must be some other problem. It just did not make sense to me that I could have 12V at the compressor and have nothing work (sometimes.) I inspected the wiring harnesses where I could and they were fine, that was when I decided to take a look at the control panel (yes, somewhat of a shot in the dark...) This did seem somewhat logical, though, since sometimes I could get the air to turn on by repeatedly pushing the A/C button on and off. When it happened to my "new" 94 940 (the batbrick) I just got a few weeks ago, I checked that first and was right on. The second time I was able to get the MCC out, re-soldered, and back in in about 90 minutes.
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posted by
someone claiming to be Greg Nottingham
on
Tue Jul 29 09:51 CST 2003 [ RELATED]
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I'll have to try that! Since last week, I have not been able to get the compressor to come on at all. I'll try the multi-recycle trick.
If it only took you 90 minutes for in and out, that beats messing with the compressor!!!
I'll let you know how it goes, but it will probably won't be until this weekend that I can get to it.
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posted by
someone claiming to be greg nottingham
on
Sat Jul 26 09:28 CST 2003 [ RELATED]
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Batbrick,
I'll have to try what you said. You just described what happened to my car. My wife said that the AC quit working. I went to drive it and I froze. My daughter then drove it and it didn' work.
I'll give it a shot.
Greg
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posted by
someone claiming to be batbrick
on
Sat Jul 26 05:06 CST 2003 [ RELATED]
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oh, the fix was to re-solder the cracked solder joint. They have both been working great since then! My theory is that as the compressor ages, it draws more current, and that the original factory solder joint can no longer handle the slightly higher current draw of an older compressor. I have a lot of experience soldering things, so it was easy for me. I would not attempt this as a first-time soldering project, however.
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Probably best to evacuate, pull a vacuum to test for leaks, and recharge accordingly. You might have a simple, easily corrected leak. Your receiver-dryer is also likely ready for replacement if there is no charge in the system.
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Advance, NAPA, Carquest, all have the fill kits that you need. I would also add a 3oz. oil charge to the system for good measure. That way you might find the leak. If you want peek performance then you need the system evacuated, checked for leaks and repaired, replace the drier, check the oriface and recharge with the right amount of oil and 134-a.
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If you insist on using a "refill kit" to charge A/C systems you are only going to 1) Do something completely illegal (charge a leaking system), 2) Do mnore harm than good in the long run, 3) wither grossly overcharge it so it won't cool, or lock up the compressor.
You NEED a scale to accurately recharge an A/C system, pressures are NOT adequate...especially with R134a!
--
JohnG 1989 245 MT @216,500
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