I have a 1996 Ford F-150 2 door long bed truck with a 5.0L Automatic transmission. The truck runs fine till you get out on the road. As you are driving the whole truck cuts off. There is no power going to the instrument panel, all the lights are off. Suddenly the power comes back on and you can start the truck for a short period of time till it cuts off again. It does this randomly, sometimes it takes longer for the problem to occur. The only thing I can think of would be the computer, but I'm not sure. Any Ideas???

 

Or bad electrical connection somewhere. A dirty/corroded battery cable can cause intermittent power issues. Try pulling codes, you never know what might pop up.

 

Mine did this when the ground wire to the passenger fender was loose. When driving it would randomly cut out and then come back on.

 

It's not going to be a computer. You are going to have a bad power/ground wire somewhere. Start the truck up and start grabbing wires and wiggling them around. Start at the battery then around fuse panel. Also try any grounds you see. If the truck shuts off, start looking for bad connections or wires around where you were wiggling wires.

 

It turned out the ignition switch (located under the steering column) went bad. The part cost $35.00, and it was easy to replace. I was told by mechanics that this is a common problem for these trucks. You have to remove the lower dash cover to get to it. The problem went away, and drives like new again. If anyone has this problem on their Ford F-150 try this fix. It is easy to do and it is cheap.

 

Thanks for letting us know.