Little Man

Alright i had posted before and tried all of the simple tricks and yet the car will still not start. I put a new engine in my N/A put a new starter , battery, checked all fusses, checked all ground that i know of..it is all wired connected except for an wire..and a few connectors that have no home...i need to get this car going and i am not familar with rx7's. The wire is brown with blck stripe. It is off of the harness going into the engine but comming from the engine the wire dosent exsist. The black box circled clicks when the car has the battery hooked up. I have power to accesories but when you try to start it it just clicks like it has a dead battery. I know it has to be something so stupid im over looking...I think the motor was out of and 88-89(not 100% for sure) and the car is 87