2.5 to 4.0 swap wiring issues and questions

I started my 4.0 swap into my 90 yj 4.0 is from a 92 Cherokee I have a complete wiring harness from an auto 93 yj with 4.0 so far I got motor and drive terrain in my jeep put most of engine harrness on an computer went to see if ignition system worked an it wont turn over started checking power to everthing an not getting any power to cyliond on starter so my question is do I have to remove the entire dash harness in my 90 and put the 93 dash harness in or could it have something to do with being an automatic computer and harness. Any help would be greatly appreciated thanks