New Engine not coming to life

got a 90 XJ with the 4.0. blew the engine, went and got one from a rebuild company, put it in, connected everything, but no start. I have spent the last couple days reading and searching with no luck. ran a jumper wire down from + battery to small terminal on starter and starter tried to turn over engine. so my thought is bad starter relay, nuetral switch or wiring. I have no idea where the starter relay is except under a cover next to the battery. I got a relay from Auto Zone but what I think the relay is doesn't match the one that I bought. It is missing a threaded stud in the middle of the relay. i need help figuring this thing out. Any help would be appreciated.

Is this a no start or no crank? First place to start is to double check all the grounds making sure they are clean and tight.

chris

no crank, the grounds seem to be fine!