[9000MAPTUN]

Ever since I got my new tranny installed two weeks ago, the AC has not been working. It blows out hot air when I have it on high, but just outside air temp when on cool. Will I need to recharge the liquid for the A/c? I haven't noticed any leaks.. anything else to check.

 

[Superaero]

Check the basics: is the compressor cycling? If not, is the fuse blown? Otherwise the problem could be any number of things. AC troubleshooting is, like most troubleshooting, a detailed but logical process.


You have no cooling (the SAAB uses a full coolant flow heater and an air blend system to mix cooler air with heated air to reach the set temperature, ther's no coolant flow control valve in the heater) but the rest of the system is working. So, it has to be the refrigerant is not flowing through the evaporator matrix (9in the heater intake in the aquarium area). The most obvious reason would be the compressor isn't working. It operates on an electric clutch on the pulley, which runs through a fuse and a relay. When the compressor cuts in and out the pulley keeps turning but the compressor drive stops, also a loud click can be heard as the clutch engages or disengages.

Next is the possibility some dumb *** emptied the refrigerant and forgot to re charge it. Next is the very common problem of a seized expansion valve in the AC system. A failed hi/lo pressure switch could be it. Also, the anti frost switch sometimes fails.

 

[9000MAPTUN]

I'm wodering if they f;ushed it when they installed the new tranny. It doesn't sound like anything has broken so I'm going to take it in tomorrow. I hope its just the fluid

 

[suckerpunch]

Ah should have spotted this new thread before restarting an older one...

For details: http://www.saabcentral.com/forums/showthread.php?p=484948#post484948

I have the exact same problem as 9000MAPTUN and at step one, I can't hear the compressor kicking in (or feel it). But because the problem was (or felt) intermittent for a little while, I suspect the fuse is fine. So what triggers the Compressor to run? Is there possibly a sensor at fault in the cabin?

Nice one for the other info, Superaero.

 

[Superaero]

SAAB HVAC is an integrated system designed by Valeo I think. The heater matrix is full flow so always hot. The cabin air temp is modulated by a neat feedback loop through an ECU. The cabin air sensor draws cabin air through the tiny vent in the center of the dash. It then calculates whether the heat needs to be increased or decreased. It then signals the AC to cool if lower temp is needed.

If the ACC does not respond normally select VENT and AUTO simultaneously and the unit will self diagnose the number of faults and deliver codes. Only the dealer can do ACCII which is on later 9000. Early cars you can do.

If the AC compressor doesn't cycle at all and the temperature is above freezing then there is a mechanical/electrical fault in the AC system itself that the ACC cannot self diagnose.

 

[suckerpunch]

Cheers for that...

It's pointing to finding out reasons why the compressor isn't kick starting then - as I tried the recalibration and that worked fine, so it seemed, no errors.

I'll have a play tomorrow afternoon and see if I can track down the loose sprocket stopping my compressor from firing...

 

[prettylittleblackbird]

SAAB HVAC is an integrated system designed by Valeo I think. The heater matrix is full flow so always hot. The cabin air temp is modulated by a neat feedback loop through an ECU. The cabin air sensor draws cabin air through the tiny vent in the center of the dash. It then calculates whether the heat needs to be increased or decreased. It then signals the AC to cool if lower temp is needed.

If the ACC does not respond normally select VENT and AUTO simultaneously and the unit will self diagnose the number of faults and deliver codes. Only the dealer can do ACCII which is on later 9000. Early cars you can do.

If the AC compressor doesn't cycle at all and the temperature is above freezing then there is a mechanical/electrical fault in the AC system itself that the ACC cannot self diagnose.

States in the handbook for my 98 saab that if the battery gets disconnected for whatever reason, that the air con system needs to be
re-calibrated. This is done by "as in post above" but Aust version is press AUTO and OFF simultaneously . The ACC display will flash once. During calibration, the display presents the digit' 0' or the number of faults found( digits 1 to 5). Calibration and self testing takes about 30 seconds.

Its also worth deleting all old settings which is done by pressing and then releasing the ' down arrow' and the 'rear demister' button. says the ACC display will flash once to confirm execution of the deletion.