Wiring harnesses are one of the unsung heroes of motorsport. These complicated nests of wires basically make the cars function the way they do, so designing and producing one requires a high level of skill and a minimal threshold for error.

This video comes from the ever-knowledgeable on YouTube. They got an insider peek at Renvale, the company that designs wire harnesses for Formula One, Formula E, WRC, MotoGP, LMP1, LMP2... you name it. And it’s fascinating as hell.

There are plenty of different ways that Renvale can produce a harness. A Renvale member could travel to the team using its harness to work alongside racing engineers with the chassis mock-up at hand. At that point, the harness goes back to Renvale, where it is thoroughly documented and replicated using the actual wires that will go into the car.

Nowadays, though, most racing teams do the design work themselves before sending their work to Renvale to be analyzed and produced. In series like F1, where everything (including the harness) is highly regulated, this is a pretty simple task for the teams, since they know what parameters they have to meet. While that homologated design is just a general overview, it’s enough to enable Renvale to create a detailed design that will actually be implemented in the car.

What I found really fascinating is that Renvale actually works pretty hard to reduce excessive variation, which means most of its wiring is white. There are things called “idents,” or tiny little tubes, slipped onto the wire to help technicians understand where certain wires need to go. I would have assumed that using entirely different colored wires would have been easier.

There’s a ton here to digest: the difference between concentric versus parallel twisting, how to determine exactly how long a harness needs to be post-twisting, how to minimize the need to replace an entire harness as opposed to a small sensor, the complicated process of testing a racing-level harness, and more. But the video does a great job of breaking it down for viewers like me, who aren’t engineers and therefore cannot speak the lingo.

Wiring harnesses are beastly. Somehow I (the resident English major and therefore generally just PR, photography, and basic machining person) got wrangled into helping with the wiring aspect of my college Formula SAE team, and just thinking about the sheer number of hours I spent twisting, labeling, and implementing wires gives me actual flashbacks to wanting to weep in frustration.

While I wish I’d had literally any instruction or preparation whatsoever before I worked on wiring, I really wish I’d had this specific video to at least give me a basic introduction, so I could realize that we were definitely screwing it up on the most basic levels.