99 F150 5.4 SCab

When I turn the key to the "on" position, everything is normal, the dash lights up, radio works, interior lights and headlights work and are bright. Turn the key to crank it, I get one click and everything shuts down as if a circuit breaker is protecting the truck from a short. Sooner or later it comes back to life and I can do it again, or if I disconnect/reconnect the battery it comes back up immediately. The battery shows 12.6v at rest.

Any suggestions would be appreciated. I am a bit of a newbie and will probably have to tow it to my mechanic, but would like to at least try to investigate beforehand without destroying the truck. Researching websites has not produced much insight.

 

Try cleaning the battery posts and the cable ends. Scuff them up using a wire brush.

The other thing is that while the bat my show 12.6 v at rest, what is it when it's cranking? It could drop down below 9 v and that ain't gonna start anything..

If that's the case, it's got a bad cell and you need a new battery...

Good luck!

Mitch

 

Thanks for the reply, Mitch. Just gave the terminals a good going-over, the negative side is one of those aftermarket clamp-together types that needed to be taken apart and wire brushed. The battery and cables are less than a year old but they were no longer shiny. Put everything back together and it fired up as fast as a brand new truck. Thanks for steering me in the right direction, the simple solution was the right one.