The Stovebolt Site Forums The Shop Area Engine Shop Ticking sound when a/c compressor kicks on

First of all this is a SBC 305 v8 with a/c and power steering...
im getting a ticking sound when my a/c compressor kicks in. as soon as a/c is turned off the ticking stops. driving me crazy... any ideas? no noticeable vibration occurs when the compressor kicks in. i have looked and can not seem to locate the problem.