99, No Start

[Hasman06]

Got a 99 that has a no start condition, guy replaced Alternator and batteries on truck because it would run good until battrery voltage got low enough to kill engine (threw parts at it). He would charge batteries up, and run the truck till he lost all power. I'm taking a look at it, found the alt/chg main 140 amp fuse blown. While waiting on the fuse, he also wanted me to adjust valves, so I did so, then replaced the fuse, and now the truck will not start, codes p1693, and p1688 came up, thinking vp44, but can it be at all related to the fuse being blown, or me adjusting valves??? Of course, he didn't mention any stall issues other that dying after the batteries went dead.