Truck will not start and it is not dead battery on 2007 Chevrolet Silverado 1500

i've tried jumping, replaced the battery. What I've noticed is that the shifter indicator that normally shows which gear the truck is in has dissappeared all together. I took my jet ski to the lake yesterday and could of gotten the rear of the truck a bit wet but no more than normal. I do not have a scanner but it is reading stabilitrack on the data screen. Could the transmission cable of come loose, or is there a neutral safety switch that could of come unhooked.