i have cruse controle in my dodge 1985 it came with the truck but when i go to set it it doesnt work, i set it all up by the book but it just dont do so great, this is the first truck ive ever treyed to build on my own to impress my father and im really trying to fix it... please help!

 

If memory serves, the cruise control module in that rig is next to the radiator. There should be a vacuum line from the carburetor to the Cruise Control unit, but it may run off of the manifold or even the brake booster (pretty much any vacuum source will do, so it's tough to say where it's wound up after decades of shade-tree mechanics). Check the line for cracks/splits and replace it if you find any. Also, check to make sure that the cruise control accelerator cable is intact and functional. That's where I'd start.