No start by key,but works when jumped.Help!!

Thanks guys,I,ve had bulk head apart and back together 10x checked under dash 8x power in.PO has jinxed me on this one.Waggin has some wiring harness,s I think I,m going to get,just to know I won,t have any electrical problems in future.I was trying to just be lucky but I can,t look at her today!It,s best I don,t.Know what I,m sayin!Tomorrow,s another day!Step back!Wish me luck!All with test light.