Shelli Haag

I have a 2013 Equinox that had the pcv problem and blew the main crankseal and since it had 125,000 miles on it, instead of pulling the engine fixing it and not knowing what other problems might be lerking and putting it back in we found a replacement engine from a 2014 with 23,000 miles and put it in, now we have done that we cannot get it to start, it is like we have no power to the ECM, we have had it at the dealership thinking the ECM needed to be reprogrammed but they said they could not connect to it (2 computers we tried) so we are thinking we have a dead short or ground issue not getting power to computer - any thoughts on where we should start? I do have auto start on it could that be causing it not to start since it is a different engine? I don't know just throwing stuff out there - getting frustrated