Ok so I have this civic it's a 95 d15 and there is a wire that bypasses the factory harness wire. It runs from a splice under the dash to the starter. Just wondering what would cause the factory wire not to work?

 

Wire could have been broken/fried. They could have also had a security switch at some point as well. I would test the original wiring for continuity to see if that's why they ran a jumper/bypass wire...