Ok, never been a regular user of the A/C but reading the posts here I've stuck it on auto and we'll see how we go. However, and I'll admit this is a new experience for me, with the A/C on I can hear a loud click from the engine bay over the noise of the engine, regular every few seconds. I have no idea what this is other than perhaps the A/C compressor. Is this normal or may I have a fault. The click stops when the A/C is turned off.