Spot Color Separations with Screens

[Guest_imported]

I'm feeling like an idiot but I cannot for the life of me figure out how to print out a separation for a blue plate with a portion of it at a 40% screen. I have a document that is set up for 3 colors. Black, Pantone Blue, Pantone Red, on the black plate I made a 30% tint of the black for one of the images. Ya, that works great, black and gray screen print out. Did the same with the blue. Took the Blue and made a 40% screen for the mountains then on the blue plate it doesn't print out. Only the solid does. Help. I know it is probably a simple solution but i'm wracking my brain here...