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Discussion Starter · #1 ·
I have a 2002 93se. I can get heat on HI and AC on Low. Fan works fine, but as soon as I change the temp setting it just blows normal air. After viewing a few messages, I cleaned the temp sensor which had a nice ball of fuzz.

Still no change. I sprayed canned air upside down (freeze spray) on the red dioed looking thing and I did get warm up for a few seconds. For some reason after a few tries of that, I can't get it to repeat.

Do I need another sensor or could be be something different. $75 is a risky try for a new sensor. Also what was weird was the fan on the sensor stays on even after you remove the key.

Any other suggestions would be great. I already have a flex pipe on order to change in cold weather. :(

Thanks
 

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If the fan runs the sensor may be good. The "diode" is the sensor element (a thermistor)

Fan should run for a while after ignition off, it is a feature, which allows the ACC to have the correct temperature immediately if the car is turned off, and quickly restarted. On the NG900 it runs for about 4-5 minutes. Most people can't hear it, so they are not aware of it.

The sensor element can be tested electrically, if you want to go that far. You measure the resistance with a meter, the ambient temperature with a home thermometer, and compare to a table.

Saab warns that the cig lighter has to be in place, otherwise the sensor may suck warm air from behind the panel.

edit:

If the fan was really clogged up, I think you have to reset (recalibrate) the ACC after cleaning it. Details are in the owners manual.
 

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Before you do anything, try resetting ACC. This is done by pressing coupe of buttons together. It's in your owner's manual. Disconnecting the battery for few minutes seem to do the same thing on my car.
 

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Try This

The AAC sensor (thermistor) is a resistor that reacts with heat/cold and alters its resistance accordingly. To check it is working, set the AAC to Auto and select a temp setting (22 degrees perhaps) and connect a multimeter across it (set the meter to measure Ohms), ie, one lead on one side and the other lead on the other, bridging the thermistor in the centre. With a can of air (the ones you can use to clean the keyboards on your PC) spray the thermistor and watch the display on the multimeter change. Also the AAC should now begin to blow warmer as the thermistor is cold thus fooling the AAC into thinking you are in the middle of winter. Once the thermistor has returned to the ambient air temp the AAC should basically shut down until it detects another change in air temp. (You can also try this with a hair dryer if you have access to 110v mains supply, or 240v here in the UK) and the AAC should blow cold. If this does not work, then maybe a new sensor is required. But as mentioned by other members, worth calibrating the AAc first. Also, clean the sensor and the internal fan with the can of air, and a small amount of WD 40 sprayed into the small fan will help lubricate the plastic bearing on the fan to reduce any noise you may have.
Hope this helps.:D
 
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