They often get dry rotted and worn out over the years causing electrical issues. This one is exactly like the OEM harness but for half the price! We love using these on fresh builds rather than cleaning a re-taping or looming a factory harness which takes tons of time to make it look decent. With this, we can just replace the harness and move on to the next part of the bike. Also if you purchased a bike second hand and someone has tampered with the factory harness this makes short work of fixing up connections!