a/c system squeal when first turned on

Hi, I had the air con in my signum re-gassed the other day and now that its working nice and cold I have been using it the past few days with it being a tad warmer, I have noticed that sometimes (not every time) that when the a/c pump first kicks in there a squeal from under the bonnet, apart from that it works fine, any ideas ?



Senior Member
You'll probably find that the noise is coming from the bearing on the pulley of the A/C compressor. When you turn the A/C on, the compressor engages and the auxiliary belt turns the pulley. If the A/C has not been run for quite a while this is likely to contribute to the noise - also maybe worth checking the belt for any cracks.