will it work for motor, if so sweet.

i was talkin so someone on here earlier and i had also mentioned that i extended the ENGINE wiring harness on both sides to reach the wiring harness that goes through the firewall, and he told me that could possible be my problem right there, because of the coax that were on some of the wires i had taken off and threw away like an idiot. so im thinkin about just buyin another wire harness....