Why would it lose all power

It will not start at all .. I came down the road across railroad tracks and it died.. Nothing no lights no horn nothing...

Suggest battery load test to 'confirm' battery and cable connections are indeed ok.

I had battery tested at advance auto parts said it was OK... By any chance are you in Inman... And it has new battery ends

I'm in VA, those battery terminal ends are prime suspects for your problem!!.. MOST of those are just for emergency repair until a proper replacement cable end can be installed... Start by checking the connection at both cable ends where they clamp to cable... Truck doesn't have any voltage from battery so start checking AT the battery itself!

OK... I will check it out thank you

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