Electrical problem
1996 GMC Truck V8 Four Wheel Drive Automatic 220000 miles

in this truck,,,i have a new battery with a good charge , and replaced the cables , replaced the alt. with another 70 amp rebuilt unit , still not charging , belt tention is good , i can charge the battery to full charge , and drive the truck till the battery drops to around 10 volts , at which time it starts missing , and eventually cuts off , engine was recently rebuilt ,,,i dont know what to try next ?,, the manual suggest replacing the fusible link , also the gauge never really gets above 10 or 11 volts , even with a full charge ,,everything else in the truck is working ok as far as i can tell.....