Truck want start
When you turn the key, looks like it is full powered up. Try to start, just clicks and all lights go out like battery dead. Take off positive cable and reattach, lights come back on. Had starter tested and fine.
take the battery cables off, and clean the rust off of the terminals. then reattach them
If you still have an issue after performing the above, the battery is toast and time for a new one. If you have a multimeter, probe the battery, I suspect your 12v or less, definitely replace it. Also how old is it, over 5 years old, yank it.
Have your battery load tested
you can have a bad ground also
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