Hi, on my 03' Jazz when I switch on the lights (full beam) and then switch the air-con on I get a slightly higher pitch noise which I can hear from inside the car (and outside) coming from under the bonnet. Initially I thought it was the compressor but when I switch the lights off I don't get the noise. I switch the lights on again and I get. It is not a loud noise but I didn't have it before. I can only hear it at idle. Any thoughts?

 

could it be your engine belt? perhaps the load
being placed belt from the alternator?
Pop the hood, and tell us where the noise is coming from!

 

Is your Radio on Auxiliary mode? If it is, turn it off. Well if that don't resolve the problem. Have your belts checked.

 

When I checked under the bonnet the noise was somewhere around where the belts are (can't tell exactly). I did think about the engine belt. I will get the service manual out and check out what the specs say about the tension of the belt etc. and see if they are slack and need adjustment.

Thanks for your help.