Here's an in-depth look inside a car's electrical system, how it works and what makes it so complex:


The video is very information dense so I've broken the topic down into six main segments:

1. Power distribution (1:04). This covers the journey of current as it starts from the battery to the intelligent power distribution module. It's responsible for distributing current into smaller, manageable circuits and houses fuses, relays and circuit breakers. It's also controlled by the CANBus with a circuit board underneath.


2. Wiring harness: (5:46) This is a bunch of wires bundled together that form lanes like a highway for electrical signals and voltages to make their way about the car's body.

3. Connectors (8:48): At the end of every harness is a connector. Each has different shapes, sizes and pins. For repair, you can depin them, and decipher their function from the pinout diagram in the wiring diagram and wire color.

4. Electrical Modules (12:20): This includes any electrical load that's connected to the wiring harness, such as the engine, body and transmission control modules, onboard computers, fans, lights, motors, etc.

5. Wiring diagrams (15:25): This scares the most of us but its pretty easy to understand. Using the wiring diagram, we can determine where wires run and to what connectors they lead to. We can also trace them to find electrical faults in the system, such as the example I gave of a power window motor that doesn't work.


6. Canbus network (20:21) : The CANBus network will integrate all of the various modules and devices across two lines, CAN H and CAN L which use a differential voltage signal to communicate binary code to each other. This allows for simplification of the wiring harness, ease of communication across modules, enabling more features and of course, easier diagnostics.

I hope you all enjoy this very basic look at a car's electrical system. This brings me to appreciate how complex electrical systems have become, and to not overlook it just because we can't see how the electricity flows.

 

i love re-purposing used toothbrushes too !
good breakdown. from what i've heard, bentley uses fiber optics in their electronics as well.