While driving RPM's drop and stalls

Okay, so for starters my vehicle started to stall while driving down the interstate. It would stall for a second the rpm's would drop then everything was normal. After about ten times of that happening by car did it again and the rpm's and oil pressure dropped and they never came back up. Resulting in my car shutting off and not cranking. So I got it towed home and we looked at it checked all fuses, wires, spark plugs, coil packs, battery and replaced the cam shaft positioning sensor. It would turn over but not crank. The next day we worked on it some more and my battery was dead. So we got it charged and continued go look for damages wires. We ended up taking the alternator off and it was bad so we replaced it. And now it will not ever turn over! The lights come on the horn works the wipers and the radio does no turn on but that can be because we took the whole dash out. (Side note we placed the crank shaft senor a couple months ago? We are stumped. Please get back with me.