Cruise Control on 99 Cherokee

The Cruise control on my 99 cherokee is not working at all. For a while, it would work intermittently, sometimes the dash light would come on , and at times it would not come on. A few times that it would work I had trouble turning it off with the switch on the steering wheel. I've read about the vacuum lines and everthing, clockspring and all.
My mechanic pulled some vacuum hose off of where it went to the engine canister and said there was plenty of vacuum.
Does anybody have any idea on what else to check ?
Right now the light on the dash will not come on at all.
Thanks for any help.