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Message: <blockquote data-quote="jarance" data-source="post: 440294" data-attributes="member: 21">OK borrow picture from everybody (sorry !)The pressure switch for low pressure should be located on the dryer of the aircon. see picture below<img src="http://i122.photobucket.com/albums/o271/pbjy/Air%20con/acpressureswitch.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" />A close up picture of the pressure switch.<img src="http://i122.photobucket.com/albums/o271/pbjy/Air%20con/acpresssw1.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" />The function of the pressure switch is to protect the aircon compressor when there is insufficient gas.Here is a schematic diagram of the aircon control. As you can see the pressure switch is before the compressor clutch & Aux fan so even though the snowflake light is on, the clutch will not engage if the gas pressure is LOW.<img src="http://i122.photobucket.com/albums/o271/pbjy/Air%20con/MikesACswitchdrawing.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" />You can test the clutch by making a jumper as shown below. However, do not run it too long cos compressor will be damage due to "dry" running.<img src="http://i122.photobucket.com/albums/o271/pbjy/Air%20con/imagesjumper.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" />As you can see from the picture below, there are 2 circular rings on the front of the AC compressor. The outer ring is the pulley which is driven by the belt. The inner ring is the pulley which will drive the AC compressor when the magnetic clutch is engaged. So check whether the inner ring is rotating or not.<img src="http://i122.photobucket.com/albums/o271/pbjy/Air%20con/Car_A_C_Compressor.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /><img src="http://i122.photobucket.com/albums/o271/pbjy/Air%20con/imagescompressor.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /></blockquote>

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