[97 Aero]

Hey Guys
I recently had the radiator replaced on my 1997 Aero with a brand new Saab Rad. I believe sometime after that the A/C does not blow cool air anymore even if it is set to LOW. It just blows a constant warm air out the vents..

Now I am not sure the two are connected or its just that the weather has been getting warmer and the A/C has been used much more frequently...

Any ideas on what could be causing this problem

 

[djtaylor]

Really haven't got much to go on so lets start with the basics:-

Does the compressor clutch engage? Check that the wire on the compressor hasn't been left disconnected.

Check the A/C fuse

Check the A/C relay

Is there refrigerant in the system? It could be that there isn't enough to activate the low pressure switch which will prevent the compressor from engaging.

It could be that the temperature flap operator has come off, the flap motor has failed or any one of a number of other problems but given that you've just had someone tinker at the front, I'd check for the compressor clutch wire disconnected first.

http://www.thesaabsite.com/9000/9000ACC2.htm

 

[97 Aero]

thats is an awesome link
Thank you
I will give a go at it tonight!

Also do you think the interior Cabin Sensor could cause this...I know before when I disconnected it to clean it since it was noisy no cool air would blow...Is it a possibility that it finally crapped out??

 

[djtaylor]

If the interior cabin sensor wasn't drawing in cabin air then I would expect the ACC to have no clue about what to do. Whether it will do warm or cold I would expect will depend on the temperature, either way it won't be what you want!

David.

 

[97 Aero]

I have the car in being looked at by my g/f's dad who is a mechanic and he topped up the R134 and the condensor still didn't kick in but he noted that when he ran some voltage through the low pressure switch it kicked in....

Is this a common problem?

 

[boxman]

there are 2 relays in the relay/fuse box near the battery on your car, 1 is for the ac pump the other is for the pressure switch control, may be you have a dodgy relay like i had this week

 

[97 Aero]

Boxman - is there any way to test the Relay?

 

[4th_Saab]

While we're on this subject, the R12 system on my 1992 US Spec 9000S also blows warm.

The fuses are good, I haven't checked the relays (which I will do once the car gets home..that's another story all together). The compressor's clutch does not engage (plus I measured 0 Vdc at the terminal with the AC button in (no climate control)).

One of the hoses that connect to the compressor (the one closest to the engine) is pretty oily within the first 6 in. of the connection.

This makes me want to guess that the hose connection leaked and dumped all the R12 out, but I'm only guessing.

Is one of the relays hiding behind the glove box?

Any suggestions of where else to look?

 

[djtaylor]

4th Saab, given that the compressor doesn't engage, it is the same advice elsewhere, in that you're going to need to first check that the low pressure switch is being operated because there's enough refrigerant in the system. If not, there's not much point trying to test much else.

Once you have established that, you can then trace the circuit to the relay and to the compressor.

My first stop would be to get the system re-charged as at least you're starting with a known quantity and it could be as simple as that. If the hose is leaking you should be able to get that addressed too. There just isn't much point trying to trace a fault when the system could be empty and you can't verify it.

David.

 

[97 Aero]

I am crossing my fingers that this holds...but from a few recommendations I took the relay out and cleaned the contacts and then took the cover off...When I did this I noticed that the relay was fried...So I proceeded to the dealer to see if they had one in stock which they didn't so I headed to a parts store and they kindly let me pop a generic one in and BANG the clutch started to turn and I had cold air. So now I will just order the Bosch OEM one and hope that this was the only problem.

Thanks guys I am glad I didn't order the pressure switch

 

[Grentarc]

why bother buying an OEM relay, when a generic one is probably alot cheaper and will work fine?

 

[97 Aero]

for the difference in price I am really not to concerned

 

[boxman]

sounds like you had the very same fault as i had :roll:

 

[97 Aero]

well its good I was not alone

These cars are funny when one person has a problem it seems like 10 others all over the world will have the same problem in the same week

Gotta love Saabs! :cheesy:

 

[97 Aero]

Well I got the new relay in and the clutch on the compressor is spinning...


BUT!....when I adjust the temps from Lo all the way up it just remains cool until I put it on HI then it begins to blow hot air

What could be causing this now?

 

[Grentarc]

cabin sensor full o' crud? or its fan is stopped... i would check it first

 

[97 Aero]

Alright here is what I have done

1) Reset the ACC unit, which brought up no codes and did not help.
2) Checked the cabin air temp sensor. The fan is spinning and I unplug it and cleaned it up and dust and such. Still did not help.
3) I took off the cover to the aquarium and located the temp flap. I put the A/C to HI and the flap moved all the way towards the firewall. Then I dropped it to 27 and the flap went all the way down (I assume) towards the front of the car. I assume it is all the way down because it did not move any farther from 27 down towards LO and there is a lot of room where it could have stopped in between at each temperature level.

So the flap arm and motor are working but what would cause it from not stopping at each selected temp?

Thanks

 

[djtaylor]

I think i'm right in saying that the flap arm won't stop at selected positions because there's no such thing as a selected position for a given temperature but I could be wrong.

The cabin sensor reads the cabin temp and will therefore influence the position of the temperature mixing flap to suit the conditions.

Given that your compressor is working, the ACC control unit is working, the motor for the temperature flap is working, have you gone through *all* the tests of things like outside air temp sensor, mixed temp sensor, cabin temp sensor listed in the URL that I gave earlier?

David.

 

[97 Aero]

David...No I havent gone through the stuff listed on the url since I don't have the equipment to test the outages and what not.

When I was sitting in the car and testing the A/C I noticed that the outside temp guage crawled all the way up to 40 degrees celcius and only after I began driving did it start to go down.
So I was thinking possibly that was faulty and was reading improper temps. When I was down there I noticed a plug which was not plugged in but I don't know if it goes any where
Here is a pic.

But the outside temp sensor is plugged in from what I can tell..