2004 5.4 Truck ran perfect until turned off 30 minutes ago. Now- nothing! When I turn the key on the only thing that happens is the following:

Airbag restraint light flickers, security light blinking, and tach flickering. There is also a pumping sound toward the back of the truck. The instrument gauge doesn't even light up.

Any suggestions?

 

Have you checked your fuses?
Look at the ones under your dash, and see if the 30amp fuse at the bottom right is blown.
If it is, don't bother replacing it yet cause it will blow again.
Let me know if this is the problem?
If it is then go under the hood, and beside the coils you will see a small capacitor/relay, with a gray wire and a quick dissconnect. Dissconnect it, and replace your fuse and try it now.

 

PS. Let me know if this was your problem.

 

Do your headlights work, including when the key is turned to START? If not, then you have either a dead battery or a battery cable/connection that has failed.

Steve