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This is pretty obvious, but check that the belt actually runs to the ac compressor. Mine was bypassed with a shorter belt by the previous owner who told my the ac was fine, and since I bought it in the winter well;oops:
 

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If the belts check out, you might need a gas recharge. You can do it yourself with a recharge kit.
 

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I'll be recharging mine soon as well - but a question: does one charge the system using the connection in the engine compartment behind the radiator (up by the headlight) or the one behind the grill (in front of the radiator) ??
 

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The compressor is at the front of the engine, third pulley from the top, below the power steering pump and the waterpump. Most diagrams show the system w/o the compressor, but there is one in Ch. 1 of the Haynes manual.

Recharge through the low-pressure port, which has a cap that sticks up behind the radiator, near the battery. It is best to stay away from the high-pressure port behind the grille, because of the likelihood of injury if the refrigerant should erupt from that side of the system. NEVER try to connect a recharge kit to the high-pressure port. BAD things will happen.

Doing minor A/C service is easy, but I usually use a pair of cotton gloves and safety glasses to recharge or test the pressure, just in case.

Auto part stores sell recharge kits which are basically a hose with two connections and a gauge in the middle. (example, Napa # BK 7652982)

R134a refrigerant, PAG-100 oil (NG900/Seiko-Seiki compressor) PAG-46 oil (9-3/Sanden compressor)

The engine should be running, A/C at the lowest setting and doors or windows open to recharge the A/C system. The ACC on cars that have it should read "LO" while charging.

One end of the charging hose snaps over the low pressure port.

The other end of the hose screws down tight on top of the refrigerant container. The thumb screw at the container is screwed in to pierce the container seal, and then backed off to allow the refrigerant or the esther oil out.

If adding oil, the can is held upside down. If adding refrigerant, right side up.

The pressure gauge is used to monitor the low-side pressure in the system while charging. It takes a few minutes to charge the A/C system on my car, much longer than I am used to on other cars.

As the system cycles and draws the refrigerant from the can, the pressure fluctuates. It goes up when the compressor is off, and down when the compressor turns on and fluid is drawn from the can. The container will get cold and frost may form on the outside as the pressure inside drops. If the container does not get cold, it is not charging. An empty container will feel noticably lighter than a full one.

The pressure readings depend on the outside temperature (higher with higher ambient temp). The kit should include a chart of full pressure v. temperature as a guide to when to stop charging the system.

When the system reaches full pressure, the connector at the low-pressure port can simply be disconnected, and the port will seal automatically. A small amount of refrigerant may escape, and should be wiped off before replacing the cap.
 

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Discussion Starter #7
that is wonderful information! I think I can do this myself and save the trip to the a/c shop -- if it doesn't work, then I can go.

Question -- does it make a difference that mine is non-turbo? You mentioned that it is by the water pump, but I thought my water pump was on the left side, if I am facing the car? Just want to make sure that I am doing the right thing :)
 

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joirhone said:
that is wonderful information! I think I can do this myself and save the trip to the a/c shop -- if it doesn't work, then I can go.

Question -- does it make a difference that mine is non-turbo? You mentioned that it is by the water pump, but I thought my water pump was on the left side, if I am facing the car? Just want to make sure that I am doing the right thing :)
Of course, if you are low, there is a good possibility that you have a leak. Tracking down a leak is a bit more involved and may require you visit a service center if you're not up to the task of using dye and trying to spot the leak yourself.
 

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Just to add a bit more info, my refrigerant was being lost through the relief valve because the system overheated. It happened because a resistor at the electric radiator fan burned out, and the low fan-speed stopped working. Apparently that is a common problem, but not known to me at the time... Saab actually has a repair kit with the resistor. By the time I found that out I had replaced the radiator fan with a new/used one.

The reason why the resistor burned out was probably broken wire insulation at the fan and a short. When I finally got that far, I found the wire was almost bare.

Another trouble area are the two A/C lines just above the front crossmember of the subframe. A plastic bracket can fail, and the lines rub against the metal. I found that one in time thanks to an earlier post on this board.
 

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Rob in Atlanta said:
Of course, if you are low, there is a good possibility that you have a leak.
This is not always true with a R134 system. The dealer server advisor will tell you that the average recharge rate for a R134 system is approximatly every 4 to 5 years on average. After working in the HVAC industry for a few years during the first round use of R134 I can tell you that the 2 things I have witnessed were loss of freon even though no leaks present and that R134 does not have the cooling capabilities of R12 or R22(mostly used in commercial and refrigeration setups) which were used in earlier systems.

I have had my 9-3's system bled down and vacuum leak tested and have no leaks but I was low on R134 so go figure. Either way charging your system is extremely easy so go for it and chill yourself out!
 

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stevehayes01 said:
... the average recharge rate for a R134 system is approximatly every 4 to 5 years on average.
That is a good point. 5 years may be a long time between charges on the new systems.

Anyone know how long the o-ring seals last before they dry out and have to be replaced?
 

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I agree there may be other causes than a leak which would require a refill with refrigerant. However, I had a leak in the low pressure hose after six years of ownership and that caused my refrigerant to be low. I didn't mean to imply that a leak was the only cause for low refrigerant. Mea culpa if my posting was misleading.
 

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Discussion Starter #14
Update

I went to a parts store and got the recharge kit. Pretty simple! Now a couple of things are happening -- 1) I hear a low hissing coming from the dash (I think)when I am driving the car and 2) the air is colder but not ice cold. Any suggestions?
 

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joirhone said:
I went to a parts store and got the recharge kit. Pretty simple! Now a couple of things are happening -- 1) I hear a low hissing coming from the dash (I think)when I am driving the car and 2) the air is colder but not ice cold. Any suggestions?
Could be a pinhole in your evaporator.

Call around to mechanics and A/C shops to see if they have an R-134 sniffer (tool that can detect the presence of R-134 in gaseous state), and see if they'll sniff your vents for free (it's not difficult or time-consuming, so they *should*). If they sniff R-134, you could be in for a charming bill.
 

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Checking a little further, I found that the NG900 and the 9-3 use different compressor oil, depending on compressor manufacturer.

PAG 100 for NG900 with Seiko-Seiki compressor, Saab # 4074787
PAG 47 for the 9-3 with Sanden compressor, Saab # 4759106

(my earlier post has been edited)
 

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My AC is blowing warm air also.

When I hooked up the pressure gage as shown in the photo above, it read the pressure as being about 85-90 psi. The ambient temperature is 75-80 deg. F so apparently my refrigerant level is fine. When I toggle the AC button on and off I can hear the engine change as if the compressor is kicking in but the air from the vents does not cool down at all.

Any ideas on what the problem might be would be greatly appreciated!
 

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anyone know what the proper brand for a 1999 SAab 9-3 would be? I'd like to do this after work tonight if possible.
 

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When I hooked up the pressure gage as shown in the photo above, it read the pressure as being about 85-90 psi. The ambient temperature is 75-80 deg. F
That sounds about right. On my car, the pressure measured with the engine and AC off is around 90-100 psi at 80F ambient. However, that just tells you there is refrigerant in the system, and it did not leak out. It does not mean there is the right amount for the AC to work at best efficiency.

The pressure to use as a guide when charging the AC yourself is measured when the AC is running full blast, at which time the reading at the low pressure port is the LOWEST.

If the outside temp is not high enough, the AC will cycle on and off, and you go by the low end of the cycle on the gauge.

According to my table, that pressure should be 40-50 psi at 80F. So at 80F I would charge the system until it reaches 45-50 psi, and then CLOSE the valve on the container. If the charging kit has no leaks, the can can be left attached to the hose with the valve closed, and will not leak much for a few weeks.

Btw, I usually wear safety glasses and a pair of cotton gloves to do this, even when only working on the low pressure side of the system.
 

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PMI, Thanks for the reply. I should have been more clear. I am getting 85-90 psi with the car running and AC on full blast. I did try checking the pressure with the car off and it seems to be about the same.
 
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