Cruise problems on Lesabre

Hi, I have a 1993 Lesabre with some cruise problems.  It sets when it wants to, most of the time I have to help it by keeping my foot on the accelerator until it catches.  Generally I can get it set that way above 60mph.  Rarely below that.  This problem started earlier this year then it went out completely.  I just had my tranny rebuilt and now I'm back to where it works intermittently.  They did replace some vac. hoses when they did the tranny so I'm thinking I might still have a bad vac. line somewhere.   The cruise light comes on all the time when I set it so it think everything is ok electronically.  Any ideas on where to start?  Thanks

to start is it factory or aftermarket?

it is a factory cruise.  thanks.

vacuum motor on the cruise control is shot, and or u have leak vacuum, check vacumm then replace vacumm motor

Thanks.  I have replaced all the vacuum lines and fittings so I'm ready to replace that then, but help me out:  I'm not familiar with the 'vacuum motor'.  I am familiar with the servo, transducer, module/amplifier, vss and such but don't know what the 'vacuum motor' is.  Is that another term for one of these parts?  Thanks.

Check the cruise control's brake switch. The switch has two purposes. One is truns the cruise control off electrically if the brakes are applied and secondly it dumps the vacuum for the cruise servo. Try taking the larger of the two hoses off the cruise servo under the hood and suck on it. If you can pull air through the switch without the brakes applied then the switch is either out of adjustment or needs to be replaced. sparky