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Discussion Starter · #1 ·
To/ All...

Today ( typical,a hot day) ACC unit has started playing up. Fan power is OK (in fact as of today blowing over powerfully in my view). However, the type of air feels the same on Auto(ACC) or Econ mode.
Tried to "Reboot" by pushing AUTO & Bottom right hand button,and following happens:

Display sets to " 0 ", fan stops, green lights count from bottom to the top, and by time top orange light comes on, fan starts again, but no air blowing out of vents.
Green lights then start counting down again, the fan speed builds up, and by time green lights get back to the bottom, the air is hacking out of vents again.
All this time, LED display said " 0 ", not 1, 2, etc...
My problem is this, nothing changes, and air still feels "normal" on ACC Auto mode, and fan seem to be working harder to compensate for the problem.

Tried removing fuse for a while etc' by the way.

Any ideas anyone please ??

Cheers, Andy
 

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Air gap on compressor?
My Air Con stopped working when high eng bay temp i.e. car in traffic on hot day, removed an air con comp shim and works fine now.
I thought the test procedure you described was normal 0 meaning no faults detected.
 

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Discussion Starter · #3 ·
Thanks SAABPILOT,
I know "O" means no faults, that is what confused m, past problems wit: 1, 2 etc have rebooted successfully.
. Not very tech minded i am afraid, so any other ideas anyone pls ?
Cheers,
Andy.
 

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As yesterday was cooking, looked forward to ACC "comfort zone" but got a nasty shock as symptoms identical to Andy's. Tried calibration
etc but no joy. This situation probably arose as I renewed the battery last autumn & haven't had the need for cold air till now.
Just thought I'd add this as maybe this is a common occurence & we are doing something wrong.
(LED's & "0" display all normal as per handbook)
Car is 97 9000 CSE 2.3T.

Thanks.......Mick
 

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The O just means the ACC has detected no faults with its four sensors.
The sensors are therefore working correctly or appear to the ACC to be working correctly for all it knows they could be giving incorrect values.
Faults with the AC system however will not show as ACC faults.
I bet the Air Con clutch air gap is a v likely cause for the symptoms Andy describes.
I have wired my car so a light comes on when the signal goes to the AC comp clutch so that way I know when the AC should run. (this is NOT the same as the AC demand signal from the ACC)
Goodluck SP Air Conditioning Packs off for Take off


electric dream site shows how to adjust the air gap
 

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Checked out the excellent Electric Dreams site & found the clutch adjustment comprehensively explained. However, decided to check if the clutch was actually being called by the ACC. Put a v-meter on the wire going to the clutch but could see no change when expected. Am I correct in assuming that this is a live feed, ie should see +12v when ACC switched on? Any wiring diagrams I have found are not very clear in this area. I took out the relay under the bonnet to see if this switches ok & all good there. I suspect I have a wiring/connector fault but want to make sure that if I wire direct from battery +ve terminal to the clutch that I'm not going to blow the "SH one T" out of the fuses.
 

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In my brief knowledge of air-con systems there is a high pressure and low pressure circuit identified by a red top or top marked "H" on the ally air-con pipes under the bonnet and a blue or "L" cap to identify the low pressure side,On the high pressure side there is a pressure switch which will cut out the air-con compressor if the pressure gets to high usually by the air-con fan not cutting in so check to see if the fan can be heard when you select to use the air-con.Also on the low pressure side there is another pressure switch that won't allow the compressor to run if there is not enough gas in the system.it might be worth checking these switches to see if they are working correctly
 

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Discussion Starter · #13 ·
saabman / anyone/.

Thanks for that bit of information. However..

Looking at my aircon block(1994 L ref CSE 2.3T), it goes as follows;

standing at front grille, battery to right, aircon unit to left, and looking at unit, on top left side of unit there is a block sitting up inch or so held by 2 bolts, between which is a black cap, rather like a large threaded dust cap, with letter "M" on it. This obviously unscrews to show a threaded hole (no switches or anthing). From this block lead a thick rubber(changing to Aluminium)pipe, dissapearing to the dash area.

Also on top of unit (central) is a thinner pipe dissapearing to radiator area ( gets VERY hot ).

On bottom of unit( right hand side as it were looking at unit from top) are 2 protuberances. One is what looks like a closed-top wheel nut cover, the other one is a plastic greeny-blue cap marked "H". Again, as other cap, it unscrews to reveal a threaded hole. Again, NO switches.

Finally, a couple of wires come from top of unit, one wire is blue which goes to the left side of unit, near the clutch/belt area of the unit. The other wire is red, leading to a plastic "fuse holder" unit ( whien seperated, it appears to be a male/female probe type connection - not a fuse), and changing at other end of holder into a blue wire (if colour is relavent) which leads towards the radiator.

My description seems very different to what saabman describes ?
The unit itself seems to click and clunk normally, and when on auto mode I can adjust the temperature LED display adjustment buttons, and it blowers faster and slower accordingly, just not actually " air con " air.

Any other ideas please, other that the fact it may just have run out of charge, and need a refill etc ??

Thankyou,
Andy
 

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The first thing to check is if the SID is sshowing the correct outside temperature. When the outside temperature sensor goes faulty, that ACC baby goes well funny.

If the outside temp reading seems fine, then I would suspect the compressor. They have a diaphragm that can spring a leak or tear, which then prevents the circulation of that freon gas through the air coooling system.

And after all that theory, I am gonna grab a rum and continue listening to that TV show in that garden in London somewhere .
 

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Ah I get what your on about,your talking about the filter/drier with two valves coming out of the top of it,sorry most valves are located on the pipework nowadays but it is normal for the valves to sometimes be located on on the filter drier,now on your filter/drier check to see if there is a small glass spy hole type thingy sorry I dont know the technical name for this thing but if it has one turn on the air con and look through the eye glass and check to see if there are any bubbles passing the eye glass as this is a sign of low charge.Also you say one of the pipes gets very hot now this is normal but the other pipe should get very cold to the point of ice forming on the outside of the pipe.apart from this I cant really help you but if you can't sort it I can ask the Air-con man next time he comes to charge a car at my work,he might know of a common fault on Saab's.
 

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I've thought of a few more things now I,m sober the filter/drier is also known as a receiver or a dehydrator depending on manufacturer now if you can find yours which I think you have (a jam jar shaped ally unit with a pipe going in and a pipe going out) if it has if wires that come out of a small unit on top of it this is your pressure switch.Also if it has a sight glass on top the way to check the charge is as follows.
With a cold engine look into your sight glass and get someone to start the engine and then turn on the air-con you should see a small amount of bubbles pass the glass but they should clear within about 10 seconds,if the bubbles continue in a constant stream you are low on charge,and no bubbles on start up means very low or no charge.
 

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You are looking for the receiver/drier, which on later cars is on low down on the right hand side of the engine compartment (left, looking from the front) stuffed between the waterpump and the inner wing. On early models it is beneath the cover over the false bulkhead area just about below the right hand windscreen wiper.
 

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Finally managed to cure my ACC problem, thanks to the boss at BPV garage in Slough. Rang him to book a service & mentioned ACC playing up, ie no cold air. Even though the relay under the bonnet was coming in, carbon deposits had built up on the contacts. By removing the relay & prising off the cover, I could see the black dust. Cleaned up the contacts with a suede brush & all seems ok! He did advise buying a new relay as the contacts have worn down & I am driving to the South of France next month. (trying to escape the British summer)
 
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