[Jamm]

Need more info.Did the truck run before you changed the switch?does the truck turn over ?The switch can be plugged in two different ways but i dont think it would do what your descibing.If your still having the same prob tomorrow i'll get a wiring diagram from work to tell you where that wire goes.It's dark here or would go and look on my truck.

 

[Jamm]

check to make sure you have power down at the starter the small wire while some holds the key in the start position.may be the start went .if not make sure to check all fuses and fusible links.

 

[dodgeguy]

make sure the battery is charged and the terminals are clean and secured. this happened to my truck alot too, I found that it was just how tight the terminals were, and how much charge the battery had. if it were the neutral safety switch, it would not even click, as that would mean that the relay has the ground that the NSS provides. also, the switch is not depressed all the way to activate the switch, there is varying degrees that will provide different connections inside the switch.

 

[motorheadstutz]

I found that there is a single blue wire in the switch's harness that doesn't seem to connect anywhere. Does anyone know where this wire goes?

It sounds like your NSS is wired up wrong. You should have 3 wires coming out of it. White, Brown/Yellow, and Violet/Black.

The Violet/Black wire is to your reverse lights. The white is from the fuse box to power your reverse lights.

The Brown/Yellow goes to your starter relay and is the neutral safety start control. This ends up being the terminal at the relay that has the strange plastic plug that has a tab that hangs over the side of the relay. The NSS circuit is completed by grounding the NSS switch housing to the transmission. Which leads to the question: Did you use RTV or pipe thread tape or something electrically insulating to seal the NSS switch? If so, that may be it (after you fix the wires). The blue wire you mentioned is probably the violet/black wire.