Cadillac Repair: cruise control, hose clamp pliers, servo test

Question
1995 deville 4.9L
cruise engaged appears on the dash, but it does not work at all!
fuse (IGN 1) is new
cable from unit that goes to fuel injection is OK (alongside the accelerator cable)
vaccuum hose is sucking air so there are no leaks that I assume there are no leaks...
Is there anything I should be looking at?  anywhere else?
Thanks

Answer
Hi Chris, It would really help if you had access to the Cadillac switch test info, cruise control output test and c/c servo test troubletrees that are in the Cadillac shop manual. Since the engaged light turns on I would assume that the switch is ok. Above the parking brake pedal is the cruise release brake switch w/ 3/8" vacuum hose. The switch tends to leak and I would pinch off the hose with some vicegrips or hose clamp pliers and see what happens. Then a servo test: Remove the connector from the servo. Jumper terminal C of the servo to ground through a fuse. Jumper term. A of servo to B+. Run engine 2 minuits to build up vacuum and shut off the engine. With the other wires still hooked up jumper term E of the servo to B+ and the servo should pull in and hold. No check the brake switch, and vacuum lines for leaks and then replace the servo. Yes push the brake pedal and the servo should release. If it releases then disconnect C jumper and run eng 2 minuits and turn off. Hook up C and servo pulls in. Disconnect A and the servo releases. No replace the servo. Yes verify ground at pin C of servo connector. Ferify CT205 term E and CT403 term A between servo connector and PCM aren't shorted or open. If ok possible bad PCM. Try the brake vacuum switch first as it is the most likely suspect. Hope that helps and makes sense. Bill