Hi thank you for your question hope this helps.
First off some questions.
Did you replace the gage cluster from auto to the manual?
Was the power trans control module changed in the swap?
Is the horn working.
Are the brake
Now you changed out the solenoid vacuum switch, Do you know if the cruise control servo is getting power.
Hear is the diagram for the cruise control
Things to check
Is the fuse #10 and fuse #20 good
Is power getting to the cruise control switch
Is the brake switch working, If it is bad it will cancel the cruise control being set.
Let me know what you find.
I plan to do this same swap to my 01, How did it go as fair as install and driving?
Hope this helps