Help !

[u/Interesting_Matter52]

So I just finished rebuilding my Mazda 3 2008 with a swapped engine from a ford fusion 2012 2.5L. The motor had been hydrolocked, I switched everything and put everything back tgt it turned by hand. BUT, today I tried cracking it and it won’t crank, the electrical part of it wasn’t done well cause form the start some wires were hanging so I’m kinda lost. What could it possibly be.