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Discussion Starter #1
Hi everyone, i'm back whit a new and weird problem on my car(SAAB95/1998 2.0T) .The problem is after i change the compresor,radiator,filters,pressure sensor charging whit freon all good and nice all this was friday , next day il take car after 2 minutes a big noise and a cloud of freon from the front of the car.All freon is gone. I go to the service again all god no error code from the AC unit. After charging again whit freon and multiple checkings the compresor is still working after the AC is OFF.
Maybe some of you have any ideea for what is causing the problem.I check all the relee and fuzes all god, really is driving me crazy,please need some help to solving the problem.
 

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Discussion Starter #4
The frustrating problem is compressor is active even the AC unit is OFF, in this case pressure is too high and blow up freon.Almost everything i try the compressor is ON and i have no ideea what is causing this.
 

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Make sure you aren't in front defog/defrost mode. That automatically tries to start the compressor.
Change the setting to feet or head. Also, when econ is lit, that means AC is off (some people get confused by that).
 

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You have a clogged valve somewhere. Not sure if these use an orifice tube or an expansion tank but that sounds like its your issue. Overpressure, basically. Did you measure the oil, use the right oil, and change the desiccant tanks?

If everything's good I'd begin looking at electrical.. grounds and whatnot.

..and if that's all fine, you've got a faulty compressor. Hopefully it wasn't "coereced" to fit into the bracket. Was it used?
 

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If it blew a big cloud of freon means 2 things. One ( obviously) a seal / hose is blown. Second is that your high side pressure is blocked causing a spike in pressure that blew what ever it did. Most likely a condenser. I always replace 80 to a 100 percent of ac systems on all cars because they are delicate systems that require specific pressures to function properly and one bad component can easily ruin the rest. My honest opinion is that the high side has a block and the system blew up before the car could see a problem.
 

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Hello, I want to thank you for your advice. But the problem is that the compressor goes in one even if the climate is off, so the pressure increases continuously until the valve on the compressor releases the brake. I think a wiring diagram would be helpful. If someone has it for this car it would be great.
 

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Discussion Starter #9
Or at least that's what I think is the problem. I'm waiting for your advice because these days it's 39 degrees Celsius and you can even cook dinner in my car. :))
 

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I do not have a diagram, but you may find one here.

If you can, I would strongly advise you take this to a shop to have it properly diagnosed. We'd be able to use equipment you likely don't have access to, and would ensure the refrigerant is recycled safely and the correct amount is refilled through the use of scales on the machines we use.

Definitely have the desiccant tank, condensor, and expansion valve changed. If the compressor was used, it's likely overheated now and no good.
 

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How do you know that the compressor goes on?

Have you tried unplugging the connector to the solenoid that engages the compressor? Note that of course the pulley is always spinning when the engine is running, the question is whether the pulley is locked to the compressor itself and turning the compressor.
 

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The compressor on these cars have variable output.

you vacuum the system with a vacuum pump for an hour or so.....then let it sit a few hours or overnight. the vacuum must hold.....or you have a leak.

then fill by weight of gas.......see WIS for quantity and directions.

my gess is you overfilled it.
 

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Discussion Starter #13
As I said earlier, the compressor works continuously even if the climate is closed as I start the engine works and the compressor does not work only with the relay removed. As for vacuuming, I took all the steps.I mean, that's my job. I install and service air conditioners and thermal power plants.
From what I found, the compressor receives the command all the time and runs all the time. What I can't find is what or who gives the order and it would have indicated a wiring diagram so that I could discover the problem.
Anyway, thanks for the advice you give me, if anyone still has or has run into this problem and knows how to solve it it would be great. Thanks again.
 

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Have you switched the AC relay? Is it possible that the relay has stuck closed? The relay is supposed to get a signal from the dash switch/controller and at least six sensors but perhaps the relay or wiring are faulty and it’s always seeing 12v for some reason.

As said earlier, Saabs use a variable displacement compressor and pressure is controlled by the “swept volume” of the pistons, not by switching the compressor on and off. You need to fix the “always on” issue first and then check pressures. Better still, evacuate and replace with the correct weight of R134-A.
 

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I don't know if you can find a Tech II. That might tell you what is going on.

Another possible thing to try is to pull out the climate control. (Is it manual or automatic?) If it is not connected, does the clutch still get an activation signal?

Finally, you can go to saabwisonline.com or download WIS/EPC from the Tech II forums here. They will give you all the details of the wiring and which module commands what.
 

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With the compressor running all the time is the high side cold?

Did you put in the proper weight of refrigerant? Or did you go by pressure.

The ECU provides ground to the A/C relay. If is running all time maybe the relay is getting ground all the time. Some of the inputs are:

1) high/low pressure sender on the passenger side of the condensor behind the headlight. Check the wiring.

2.) out door air temp in the top cdnter of the lower grille. This also provides a reading to the SID outside temp reading.

3.) Coolant temp.

There are a few more. Check you WIS.

If you have neither WIS or tech 2 , you are at a disadvantage. Luckily you have HVAC experience, and you need to apply that to the system in the SAAB 9-5.

Know the system high pressure that the bus and therefore Tech2 sees is an important starting point.
 
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