I have the identical cruise control system.
I went thru hell figuring it out...first replaced all 4 lines.....the multifunction switch twice
...then checked out the brake switch. It turned out to be the actuator.
Does it hold the speed at all?
check the top vaccum hose.
note my photo here. The green are the hoses that fail, the red is the actuator that failed on my 94.
We really need to know whether it tries to engage even a little bit...if it does even the slightest ammount try to hold a speed it is 98% a bad line somewhere you missed...there are many areas where a vaccum line could break.
If it does not try to engauge at all it may be a dead actuator or brake switch or multifunction switch.