Cruise Control Problems

I've been having a problem with the cruise control in my '96 Jetta GLS for some time. Sometimes it will set but more often it will not. When it doesn't set I hear a clicking under the dash from the relay.

Does that mean the relay is working / not working?.

Secondly, when it does set it will slowly drop in speed. I can't seem to find any consistency in it's set vs. not set routine in hopes of determining what is causing it.

Any input would be much appreciated.

The cruise control has a control unit on the back side of your consol. The throttle is operated by a vacuum actuator (sp?) that attaches via vacuum hose to the consol. You can follow the cable from your throttle body back to the vacuum device. There are vacuum switches on your brake and clutch pedals that basically break the vacuum when either pedal is pushed. When the vacuum is broken, the vacuum pump shuts off (source of your click). It sounds like either a switch, actuator, or vacuum line is leaking. Check your o-rings, hoses and fittings for leaks.