Fuel Pump wiring ?? ?

My son's 96 Blazer fuel pump will only come on sporadically. When I wiggle/move a blue wire that connects to something that is screwed into the block on the drivers side and then into some sort of connector that ultimately goes into a wiring harness over to the passenger side engine . The haynes manual doesn't help. Please help on terminology and schematics.
Thanks
Paul

Maybe this will help:

http://www.image-hosting.ws/direct/305.jpg

We need to see a picture of this.

You explanation is completely confusing and doesn't really yield any information to help you solve the problem.

Please be more specific and post a picture of this wire.