And the past 12 V systems are dead easy to work on. On older cars that is, as soon as you have electronics and bus systems DIY basically requires deep car electronics knowledge and skills.
I haven’t done a ton of work on newer cars, but at least adding wiring for a hitch on my Kona EV was just as easy as any wiring I’ve done on my old truck.
Is a job like adding amps and better speakers trickier?
My 1982 Range Rover has all of three fuses, so electrically I'm fine! Except the mess previous owners did to the original wiring... No idea why it is so difficult to just make your own wiring for after market accesories instead of butchering the OEM one up beyond recognition. It works, so I don't touch it. I have no idea why it works so...
> I have no idea why it works so...
I know that feeling haha. Adding wiring is so much easier than ripping up existing stuff ...
Hence, one needs some good knowledge around that, what to connect where.
In the old days, well, just go directly to the main battery with your aftermarket wiring and Bob's your uncle.
And none of that, battery management, which equipment can be connected where, has anything to do with the voltage but rather with all the other stuff modern cars have (bus management, battery management, ECus,...) all of which might or might not accept voltage and amp fluctuations very well.
So how is this done on cars? Dores each manufacturer have their own proprietary bus system (what i imagine), or is there a standard that everyone can use?
Protocols like CAN, LIN, SENT and XCP are all standardised point to point and bus protocols for automotive stuff
I personally think the standardisation is actually a bit limiting[1]
Just like SpaceX found massive cost savings in using networking tech over hard wired interconnects, I think there’s a good chance China or other manufacturers might catch on
[1]I think interconnect failure rates are so low out of factory it’s not unethical to begin making things more lean, obviously with sufficient human safety testing
But I’m not an expert, just a former engineer working in an electronics shop…