Audi Repair: 2002 Audi A4 electrical relay clicking, 2002 audi a4, fuse box

Question
There's a rhythmic clicking coming from the panel near the fuse box (driver's door, under dash) that sounds like a relay clicking on and off.  It runs on a 2-second cycle, on-off..on-off...on-off...on-off.  And it does so predictably only when I am actively accelerating, and only on flat or uphill grades.  But then it will continue until it drives me nuts!  Ideas?  Not concerned, but desperate to get my otherwise supremely quiet car back again.

Answer
First thing to do is to remove the lower dash cover, and establish which relay it is; this can be done by putting your finger on the relays until you can feel the one that is clicking.  If it only does it when you drive, this may be tricky.  Anyway when you discover which relay it is,  let me know.  Jan