It won't crank? Battery is dead?
If it is a cranking problem, then are you sure the ground wire from the engine to the truck body is good.
If it is going dead, try this. Take the ground terminal off. Put a 12V bulb between the battery terminal and the cable. If it lights up, something is drawing current.What can cause my battery to not hold a charge?any short can draw the juice out of it. if there is a short in the starter it can cause it because your hot cable runs to the starter. a bad ignition switch is another thing.What can cause my battery to not hold a charge?The ballast resistor , a ceramic item about 1/2 inch by 3 inchs mounted on the firewall is most likely the culprit.What can cause my battery to not hold a charge?Sounds like an electrical problem. You should have it checked by a mechanic that is experienced in mechanical work.