T.LAYF150

Over the last few months, I have had the issue of my truck not wanting to start on several occasions. Most of the time, it is first thing in the morning, and somewhat cool outside. I put the key in the ignition, turn the key (interior lights, ac, and radio are all operating normal), but when I go to crank the truck nothing happens. No clicking from the starter or anything. One thing I have noticed, is that whenever it does this the orange "p" on the dash is not illuminated orange. It's just dark. However, the R, and the drive gears all light up orange when shifting to those. Half of the time, you can shift it to neutral and the truck will crank up in neutral. But here lately, it is not sensing thay the truck is in neutral either. So I will sit there shifting it back and forth and taking my key out of the ignition and putting it back in until it works. I've taken it to 2 different mechanics, and both of them have ran diagnostic tests on it and it comes back normal. Nothing that they can see is wrong with the truck. The second mechanic claimed that it was the shifter cable, and that he tightened it up and it crunk fine everytime after. But the next morning, it would not crank up. Do you guys have any idea on what the hell this could be? I'm starting to think I'm going to have to invest some serious money into this to pinpoint the exact problem.