Hey Guys, My name is Rick. This is a weird problem, maybe someone can please help me...I have a 1997 F150, Extended cab with a 8 foot bed. When I go over bumps (big or Small) the truck loses complete power....engine turns off and there is no power for about 3-5 second and then the truck has power again. BUT it doesn't happen all the time. It can be dry or wet outside, it doesn't matter. I replaced starter cables and battery leads with terminals for the battery. Any suggestions? Thank you very much.

 

sounds electrical to me which i am not very good at...does check engine light come on when this happens?? have you checked to see if you have any codes stored??

 

As fordman said I'd check for codes, but that type of a immediate failure is similar to a crank shaft position sensor type issue. I'd go and check the connection, check the sensor itself if possible and make sure its secured. This is going to be a pain in the butt to diagnose because you cant replicate the problem without putting your truck on a giant paint shaker. so good luck with it and start by checking codes then all connections to major sensors.

 

Also could be the throttle position sensor

 

Maybe try a wiggle test to narrow down the search. Grab every wiring harness you can access and wiggle them while truck is running. With any luck you'll be able to find which harness is the problem-go from there.

 

Mine did the SAME exact thing, and it was little selenoid on the firewall right behind the battery. The nuts that hold the power cables onto it were loose.

 

same here check those bolts

 

Maybe fuel pump ? only a thought.