In the last couple of days the ECON light on my B6 A4 (2001) has come on and refused to be turned off and I've also noticed a small leak from the engine bay. Seems to be a colourless liquid dripping very slowly. I'm assuming the 2 are connected and it's something wtihin the air con set-up that's leaking which is causing insufficient pressure for it to work properly? Am i right? If so, what is it that's likely to be leaking and how big is the job to fix it?