Youre probably right someone else did it while he watched then they walked away when it didn't start and he was left with it
And if that is the case, he has crap friends, the post reads as if he did it himself. If he paid someone (garage) he wouldn't be asking this question.
I would gladly help if I could but there are so many possibilities it is pointless. Maybe he plugged a wrong sensor in somewhere, maybe a little ether would help, maybe he didnt do this or that, very broad question he has asked.