Ok I have a strange one truck has been running and driving fine and then the other day went out and no start no crank, acting like battery dead at first. Installed new battery and same problem. Got to looking at it closer and I connect the battery and the power door locks and everything work fine until I turn the key on, turn the key on and takes a few seconds for the instrument panel to power up, and after it does I only have the airbag, abs, and battery light on. Radio doesn't work and everything that seems would run with the key in run is inop. Now when I turn the key to the off position the instrument panel stays on I have been looking on other forms have seen similar concerns with fuse block under hood... Anyone else got any other ideas ??

 

I would check the battery cables at both ends, especially the ground cable. Corrosion or rust at the ground cable can cause many electrical problems.

 

ok little bit of an update got the truck running everything seems to be acting normaly, what i found was i was checking everyground i could find on the truck id clean them and reinstall and nothing was changing i work at ford and i have access to alldata and spent about 2 hrs looking through wiring diag to determine a common cause with everything that wasnt working (dash lights ect) what i found is a ground on the pass side, back of the engine block by the bellhousing under the intake manifold. it comes from the main engine harness and is a ground for the pcm. well in my case it was ate in half by rat but repaired that ground and everything is back to normal hopefully it stays that way thanks "oldchevy" for the help hope this helps someone else out