81' 22r 4x4 cold start prob.
Please HELP!

I am stumped..... If my truck sits over night or for 10 hrs...it loses spark and will not start unless i double jump it...after the morning jump it starts fine through out the day unless it sits for an extended period of time...now let me run through the gammit of things i have done to correct this problem.....RR plugs,wires, magnetic pickup,cap, rotor,igniter,coil, battery, checked and cleaned all grounds, checked all wires for shorts, its not fuel related, I keep comming back to battery, but on load test its great....14.2 external volts and on load down to 12.5 then straight back up! ...

 

Any wires that come directly from the battery may look good on the outside, but on the inside, be corroded to the point where it wont allow enough voltage to start the truck without the help of a boost. Cut open the insulation as close to the battery as possible and see if it's clean copper or green corrosion. Buona fortuna! (good luck!)