Using one kind of unkeyed connector in a car may be a bad idea. Things can be plugged in wrong during repairs. There's a lot to be said for making connectors not fit where they shouldn't. Especially in automotive, where many connectors are plugged in blind, by feel. This simplifies manufacturing at the cost of repair.
If it can be plugged in wrong, it will be plugged in wrong. AAA put a battery in backwards in my Jeep once, and most of the vehicle electronics had to be replaced.
Actually there’s two paths: first the traditional path of different unique wiring harnesses and various signals with unique connectors, or second a common power and coms bus design.
If the Cybertrucks electrical ethos is followed by others there’s only 48V and Ethernet. Ethernet doesn’t care or fry if plugged into a wrong port. Any complex wiring can be done inside a part or component as needed, but the interface is one of a few options.
Let’s say the window motor is plugged into the power and not the switched motor plug. As long as it’s a 48V motor it’ll just turn but not fry. You just unplug it and reconnect it.
IMHO industrial everything should become 48V Ethernet. Just like for gadgets usb-c rules the roost.
> If the Cybertrucks electrical ethos is followed by others there’s only 48V and Ethernet.
I'm looking at the electrical schematic [1] and 'eth' appears 107 times while 'CAN' appears 805 times.
And if you think about it, you probably don't want your brake-by-wire system to share a bus with your sound system and your trunk latch for obvious reasons.
Cool, thanks! It looks like the cybertruck does extensively use CAN still. Tesla only talks up Ethernet.
Makes sense, though I’m a bit bummed.
> And if you think about it, you probably don't want your brake-by-wire system to share a bus with your sound system and your trunk latch for obvious reasons.
Sharing a bus for those two wouldn’t make sense. However Ethernet topology wouldn’t preclude having those on separate buses and linked via switches.
Though that’d pose problems with my view above about plugging anything in anywhere. Though it’s really more of a philosophical goal. ;)
> However Ethernet topology wouldn’t preclude having those on separate buses and linked via switches
The topology might not care, but someone designing a trunk latch that communicates via Ethernet might get a visit from an annoyed representative from Value Engineering.
Haha touché. However unintuitive as it may seem an ethernet based trunk latch could be overall cheaper from a system level than a straight relay based system or even CAN system.
Especially with the newer two wire ethernet with power via 10BASE-T1S. The connector likely costs more than the ethernet chip, and microprocessors can be had for nickels. So at large manufacturing scale it could easily cost less to share a single ethernet and power line and save on wiring, connector complexity, etc.
Different quality of service requirements. The infotainment system is complex and it failing is just annoying while the brake failing could mean death.
There's a high voltage (800V) rail for high current devices like the AC compressor. There's redundant CAN for communication with things like the motors. There's a host of 12V, 16V, 5V components (door locks, lights, seat motors, etc.).
They did switch many components to 48V, but not literally everything.
One of my takeaways from my time as a RATELO is the thought put into connector design. Everything in the Army was designed to plug into one thing and one thing only to prevent mistakes.
> Using one kind of unkeyed connector in a car may be a bad idea. Things can be plugged in wrong during repairs.
I tried to lower the window in a Ford shortly after leaving the dealer. It fried the lock. Somehow they were connected together by accident. I agree dumb wires should be hard to mix up like that - both via orientation and similarity.
These looked keyed to me. Aside from the bulge on the top of the connector where the lock attaches to it's mate there is a middle vane that extends 2/3 way down with a little bit of a J hook on it.
I think by keyed it isn't just "can't be plugged in upside down" but also "can't be plugged into the other plug that's basically the same but connects to some other subsystem."
Ideally a system like this would let you select some per-subsystem physical lockout mechanism.
The plug manufacturer has to provide many, many keying options (say for a 2-pin plug, one might have variants 2A, 2B, etc... which explicitly cannot mate with each other)
An engineer designing the car has to ensure all plugs with same keying options are interchangeable (2A is for power supply; 2B for door switch; etc...)
If the plug manufacturer does not provide enough keying options, this will be pretty hard to during design time.
Connectors with distinct shapes and sizes are usually used. If it feels like it could go in then it's the right one, and if it goes in it easily seats fully and never comes out without a tool. Wrong connectors don't even feel like they could go into wrong locations.
Cars using whole bunch of different connectors relying on whole bunch of suppliers is feature-not-bug situation. It is optimal for large scale volume production; work will be more distributed, SPoF will be more localized, etc. Standardized connectors with trivial visual differences and/or field configurable keying is a suboptimal solution for car problem. Usually.
...is it a local minima for small scale production? Are they having issues with scale outs, and therefore seeking downward scalability?
I work in this space and 100% agree, in fact I have been on a bit of a crusade to get the mechanical guys to stop designing parts that are rotationally symmetric for this exact reason. Letting a set of three parts be installed 17 different ways isn’t “keeping our options open” it’s “fucking up maintainers.” Each part should fit exactly one obvious place. Each connector should plug in at exactly one obvious place. The only exception is when it doesn’t matter where the part goes, which is approximately never.
That said, sometimes there are cases where an entirely new connector style isn’t warranted, and that’s where you use blanking pins or adjustable keyways or whatever.
That's the latch, not a key. Keying prevents putting the wrong plug in a receptacle. Usually that's done with notches on the receptacle and ridges on the plug.
Well that's a lot to unpack. Saying AMP connectors doesn't really mean much of anything because, for starters, AMP (TE Connectivity) owns Deutsch.
In the retail space, at least, DTM's largely been superseded by the lower-cost ATM line. Weatherpack and Metripack are pretty common in the US because GM developed them and GM is a huge company. The only company that comes to mind for using DTM connectors is Caterpillar, so you'll definitely see medium duty trucks with DTM assemblies.
The two automotive companies I'm most familiar with (80s Volvos and 00s BMWs) use keyed connectors all over the place. The Volvos used off-the-shelf washing machine connectors (AMP /(junior )+(power )+timer/) that can be had with keyed connectors. BMW saved pennies by going with high density connectors and small gauge wire. Most of that stuff is off-the-shelf as well, but often with proprietary keying.
Both DTM and Weather/MetriPack are pretty bulky compared to what's available now though, and when you're talking about 100 or 200 pin connectors size probably matters more than a few pennies. And, of course, once you start adding the retention doodads to MetriPack assemblies you start getting closer in price to DTM style stuff. The simplicity of the wedgelock design means fewer parts to stock and potentially faster assembly which could easily negate the more expensive housings.
Tesla really deserves some kudos for pushing the 48V architecture and the Ethernet-based communication. It drastically simplifies the wiring mess that is in a typical car.
And it's not even close. Just watch the teardown of Cybertruck and compare its wiring to something like F150.
This has been a real head-scratcher for me. BMW and other automakers could have vastly improved their cars by switching to 48V a decade ago, but they still keep just plodding along with 12V.
It's a classic chicken and egg economic problem. BMW doesn't make the chips/electronics that support the 48V architecture - Bosch & Continental (with NXP/TI/Infineon/Renesas as their silicon suppliers) do and they're not going to support 48V unless ALL (or a significant majority) of the automakers will. So it's a game of chicken.
I designed some stuff along these lines 15 years ago. At that time, 12 volt stuff was not just available, it was available with great economies of scale and a huge range of options, off the shelf. You need an automotive-qualified relay? A light? A solenoid? A DC-DC converter module? A fan? You'd have 100 choices at 12v, 30 choices at 24v and 3 choices at 48v.
Are BMW cars less reliable, expensive, not ready for zonal assembly...?
Major car components like doors or front axles are assembled in parallel to miscellaneous parts on the main body, and all .join() at the final assembly. This had been the case for past 30-50 years, possibly more, in case this needs to be said.
They can be even more reliable. And they definitely _are_ expensive.
> Major car components like doors or front axles are assembled in parallel
And doors (and tailgates) are the biggest body component that is _sometimes_ assembled independently. Then workers manually route cables through the body.
Pre-routing cables inside panels that can then just be welded together can save a lot of labor.
> And doors (and tailgates) are the biggest body component that is _sometimes_ assembled independently.
Sometimes? What and when on Earth is this about? Pre-WWII?
They wash and paint and dry the whole body at once _for paint consistency_, then take off doors and trunk lids and bumpers and send them into separate assembly lines. Those major parts flow parallel "threads" in sync and converge near the end, where connectors are plugged in and those major parts are bolted back in and plastic trims are pushed in to tuck everything under. Cars were basically always done that way for a long time everywhere. I think even lots of hand made supercars are like that, only except tact times are magnitudes longer.
> Then workers manually route cables through the body.
> Pre-routing cables inside panels that can then just be welded together can save a lot of labor.
What do these even mean? Are you hallucinating workers crimping cables in-situ? They just clip on harnesses and plug in couplers in "the line". Never seen under a door trim?
It sounds like you're either extremely ill-informed, or worse yet, potentially, intentionally misinformed about car manufacturing that what you see is advanced manufacturing. I think you should... look more closely into what "legacy auto" have been doing forever.
> What do these even mean? Are you hallucinating workers crimping cables in-situ? They just clip on harnesses and plug in couplers in "the line". Never seen under a door trim?
Workers still need to pull the wiring bundles through the car body and clip them, after the body is welded together. The connectors are impractically bulky to put several of them along the cable routes.
Pre-assembled panels can have cable runs attached to them during the individual panel assembly.
They don't need to retool all the factories at once. They could have gradually introduced 48V systems in parallel with 12V, slowly phasing in new components as they replaced the old 12V.
Converting between voltages is not a free action, and running two systems is more complicated than one...
You really need some special component that is much better at 48 for it to be worth it, otherwise a delayed platform switch is better; one some competitors have moved and the suppliers exist.
On top of all that, almost all the wiring in the car can be made thinner, because of the greatly reduced losses. This saves a bit of weight, but also a lot of cost because copper is expensive.
There is no free lunch. You need to go to a finer wire strand, better insulation, better loom, better support for the harness etc, if you want that super fine wire to last. Some of those have pretty direct labor cost impacts too. That's gonna kill a lot of your cost savings, especially at lower production volumes where the design cost is harder to amortize. There's no free lunch.
It's very, very hard to get insulation that's not good for at least 100V and I suspect that just about any generic wire is good for more like 300V.
The only exception that comes to mind is wire that's specifically for "household low voltage" like 24V AC for thermostat, doorbell, sprinklers, landscape lighting. Also normal ethernet. But these are almost all what you'd call signalling wiring rather than power wiring.
Your average hook-up wire that you could buy at the auto parts store to make some repairs is almost certainly rated for 300V already. Mostly because of chafe resistance. Wikipedia says that the dielectric breakdown strength of PVC is 40 millions volts per meter https://en.wikipedia.org/wiki/Polyvinyl_chloride.
Divide both sides by 1 million and you get 40 volts per micron. OK so you need 1/3 of a micron to insulate enough for 12V and you need 1.25 microns for 48V. Now let's have a reasonable safety factor of say 10 or so and we're looking at 3 microns vs 12.5 microns. The only wire I can think of that might have insulation that thin is enamel coated magnet wire for the inside of motor windings. But even that is probably thicker.
Any kind of plastic insulation is going to be significantly thicker than this just to be able to be coated onto the bare copper wire and stick.
You're not wrong that the insulation needs to be thicker as the voltage goes higher. But you're unaware of just how ridiculously over-insulated everything already is due to other constraints of manufacture.
I'm sorry but the other comment is more correct. 48V standard was originally created for mild hybrid systems for ICEs during mid-2000s as a stopgap solution to full hybrid transition. Looks like the earliest mass-production 48V-class system was a 2001 Toyota that ran at 36V.
The integrated starter generator(ISG) is usually a pancake shaped motor that replaces clutch/torque converter in ICE car, nothing like the regular starter motor.
MHV was not even real hybrid, and is no longer relevant, so was 48V, at least for a while.
The special component was supposed to be the starter. With start stop systems essentially mandatory, the starter runs much much more often and therefore wiring savings on the starter are pretty useful…
How about comparing it to a teardown of a Rivian? Rivian uses 2-wire ethernet but 12V, so it seems like a more interesting comparison.
That said, it all seems like inside baseball to me. The BMW 850i pioneered the CAN bus, but that car was forgettable and although CAN bus took over the car industry that did not seem to create any durable advantages for BMW.
Ethernet seems like the inevitable replacement for CAN, in light of VW's investment in Rivian, and 48V vs. 12V for the low-voltage systems seems like a wash.
CAN is slow. At best it's around 1Mbit, but you get into electrical limitations. So you have to run multiple CAN buses in parallel and carefully manage bandwidth limitations.
My Chevy Volt had 4 different CAN buses and one additional LIN bus.
This can all be replaced with just two Ethernet buses: for safety-critical and non-critical uses. And the gigabit speed provides plenty of bandwidth for any reasonable sensor traffic, even including camera feeds.
The current architecture was justified in 90-s when LIN PHYs were an order of magnitude cheaper than even CAN PHYs. Now Gigabit Ethernet PHYs cost less than a dollar.
It's unlikely that the multiple CAN buses are being used to increase speed by, say multiplexing them. In general, vehicles use multiple CAN buses for enhanced security. For example: things like diagnostic ports are often on their own CAN buses so data can't be directly injected into onboard systems.
All but one CAN bus in my Volt were connected to the OBD port. The unconnected bus controlled the high-voltage battery contactors and some other critical stuff.
The "main" bus was saturated with data, more than 80% of bandwidth utilization at 512kbs. And it kinda had a mix of everything, from street names to be displayed on the dashboard to ECU messages. The other two buses had some random messages, with no rhyme or reason for the split ( https://vehicle-reverse-engineering.fandom.com/wiki/GM_Volt ).
FSD will benefit from high-resolution (4K or above) camera feeds (for things like reading signs and detecting small obstacles). You can do this in a 10Gbps network and have tons of headroom for every other function the car will perform.
Why would you not? Tesla is sending even the infortainment data stream through that bus. It's incredibly helpful having all data travel on a singular wire because you can tap in at one point and read it all out. Makes the entire system significantly easier to debug, understand and develop against.
It's a good thing we invented video compression and hardware codecs/encoders a long time ago.
What you'll actually be sending is a high bitrate mpeg stream, probably 54Mbps or thereabouts, you could probably fit 50x camera streams on a shared 10Gbps bus.
Ethernet can handle real time now even in bus configurations!
10BASE-T1S is a new standard geared for automotive. It uses physical layer collision avoidance instead of classic Ethernet exponential backoff. This provides deterministic maximum latency.
Though you can get max latency guarantees with switched Ethernet and the appropriate switch QoS and hardware.
This sounds like the real answer. Replacing an automotive standard with Ethernet is going to reduce friction onboarding junior webdevs with MacBooks, and enable a more stable higher turnover labor intensive organization.
You can already do this trivially with Linux vcan[1] so I don't buy this argument.
I think the bigger factor is that innovation in the CAN ecosystem has been lagging behind Ethernet for decades now. Only reason it's had such staying power is industry inertia.
The relative cost is probably a factor (which overlaps with inertia of course, but if the thing you already have implemented is also cheaper, you aren't going to hurry up and change).
CAN has desirable electrical properties (e.g. hardware-level prioritization) if you have life-critical devices and non-life-critical devices on the same network. But it's painful to deal with from a software point of view, compared to IP-based protocols, for anything that doesn't require the properties of CAN.
Not that I know of --- it's a figure of speech to compare it to an standardized method of electrical wiring in buildings that eventually got replaced with better standards despite similar concerns at the time.
How is this better than all the other 48V connectors out there (MX150, MCON, PP, etc.)?
Surely it isn't just that they reduced the number of connectors since one could have just standardized on a subset of mass-produced connectors by molex, te, etc. instead.
> Today a single vehicle typically requires over 200 connections—and the number of electrical
I initially thought this was referring to the connector between the charge port on the EV and the charger base station. Had to think for a second and realized it’s the electrical connections between the various components in an EV.
Glad to know I don’t have to carry 200+ dongles in case I buy an EV.
These are talking about 48V, so my guess is it's for all the little bits (window motors, wipers, all the internal electronics, switches, turn signal lights, etc etc)
To be honest I'm kind of surprised by the low number. Though I guess each connector has two sides, and they can have tens of pins per connector on the bigger ones.
(Semi-permanent) High voltage connections are usually made with spec-torqued bolts, not plastic connectors. These are for the "low voltage" (<=48V) components spread throughout the vehicle.
> Tesla invites all device suppliers and vehicle manufacturers to join us in this initiative.
This is not a standard in the sense that engineers use the term. Tesla is hoping it will be adopted as a standard and since Tesla doesn't appear to want to involve any standards bodies, Tesla appears to only be interested in making these connectors a de-facto standard.
IDK man, when I think of standard connectors I think of clunky junk: CCS which was all engineering and no focus on human centered design with its clunky connector that also wiggles in ports.
all of the USB connectors including USB-C, with it mandate to support so many different edge cases that cause cables to not always be compatible with each other defeating the purpose.
Bluetooth again with so many edge cases that made it terrible until Apple came along and cut a lot of that out in their solution finally made it tolerable.
Hell even a lot of electrical connectors (such as the US outlet) suck: developed in that way due to historical interests, it looks terrible, is not entirely safe (ie. ground does not go in first) and now has stuff bolted on to make up for its shortfalls. (GFCI, in line fuses etc.)
Now there are probably loads of terrible proprietary connectors but it seems like the free market eventually takes care of disposing of the chaff. That itself is a forcing function to get to a better design that users will like. Whereas you have no choice of a standardized connector because some "standards body" made up of opposing interests artificially keeps lousy designs around and forces it upon the population.
Im not arguing for one or the other but its just annoying that standards bodies always seem to get a pass when in my experience they produce a lot of mediocre stuff.
The points of standards is that they solve one or more problems for many constituents well enough so that all adopters gain in things like supply chain, design ease, and interoperability. They are rarely going to be optimal for every specific use case. They also often derive from specific designs by a specific company
Adding a standards body into the mix is going to add complexity to the process by definition, but shouldn't be taken as a default "bad", since there are tangible benefits to non-corporation-managed standards. Otherwise they wouldn't exist.
Name the “wildly successful” standards you are thinking of and then look into the history of them. You’ll find one or maybe two major players that pushed it initially.
Yeah, there are advantages to the "just do it" approach to standardization vs design by committee. A lot of web technologies started out that way (arguably most of them actually). Both approaches are valid.
I agree. Is this some kind of free licensing for these connector standards or are they still behind the "you can use this but if we rip off any of your IP and you sue us we'll revoke your license and sue you" license?
They have a "patent pledge" for their patented parts, at least -- they will "not initiate patent lawsuits against anyone who, in good faith, wants to use our technology".
Yeah, and they define good faith in that document as:
A party is "acting in good faith" for so long as such party and its related or affiliated companies have not:
asserted, helped others assert or had a financial stake in any assertion of
(i) any patent or other intellectual property right against Tesla or
(ii) any patent right against a third party for its use of technologies relating to electric vehicles or related equipment;
So, if another company rips off your IP but Tesla doesn't think it is a "knock-off product", you sue that other company, you're now in violation of Tesla's "patent pledge". Its an attempt to use a carrot of Tesla's patents to make all the other rightsholders essentially give up all their IP. If you sue anyone protecting your EV IP, you're in violation of this agreement and will be open to litigation by Tesla.
There are different types of standards. Car design teams are big organizations; internal standards can help reduce the development effort. Tesla needs to coordinate with their suppliers, so sharing this helps even if it isn't used by other companies.
I think we should give Tesla the benefit of the doubt for now. Harmful use of patents could cause issues, but this has potential. We will simply see if other companies are interested, and if they are it can go from internal standard to de facto standard to formalized standard.
Don't think of it as a standard as-in SAE, but a standard as in "molex", "AT", or "ATX". Yeah, they aren't really "standards", but they aren't exactly proprietary either and they also are clearly useful.
The goal seems to be to promote reuse of a good-enough design in as many places as possible. Noone's forced to use it, but it'd make things simpler for everyone if there is as much commonality as possible.
It's going to be a standard within Tesla, so in that way it's a standard. It sounds like they anticipate benefitting from cost reduction themselves even if nobody else uses it.
Most useful standards did not originate from standards bodies. The standards bodies just formalized what already had buy-in from the significant players.
The XKCD doesn't really apply here, since intra-vehicle 48v is kind of unexplored, so there aren't multiple competing standards for that in particular. I do agree that this isn't a real open and free standard however.
True, but Inter-vehicle could be cool for several things. First is the EV equivalent of jump-start-and-bring-a-can-of-gasoline, an in-the-field recharge for cars that run out before the recharging station or home charger. It would also be useful as a plug for a range-extending spare battery pack on a small trailer. Seems like other potential uses too.
(But no, I'm not liking that Tesla is taking the typical entitled-ass attitude of avoiding all the standards bodies, doing whatever they want, and expecting others to ratify their standard. If it is that good, it should be readily agreed to by the relevant standards bodies.)
That's entirely possible at present. Many electric vehicles can send power out to power appliances. It's called "Vehicle to Load" or "V2L".
And electric vehicles can slow-charge off a wall power socket, so they could get that from V2L. It won't be a common use, but it would work in a pinch to get you enough juice to get to a better charger?
Why is it that when describing EV technology, HN people have a tendency to frame it as "imagine if it could, that would be amazing if"
While describing stuff that exists in some form, and usually has existed for years already now.
It's not evenly distributed new tech for sure (1). But maybe it's the false assumption that "if it was anywhere, I'd be among the ones to see it early".
1) See William Gibson: "The Future is Already Here, it's Just Not Very Evenly Distributed."
Other people already mentioned safety. But you can actually go to 96V if needed by running a cable with -48V if you need extra power.
One another advantage of the new 48V architecture is that it doesn't depend on the car body for the current return path. This opens up possibilities of adding sensors that detect current leakage, to pinpoint areas with defective wiring and/or components.
Depending on the country you live in, the laws might allow you to do work on equipment that is below 50 volts, but require you to be a certified electrician for anything above that.
The phantom power at 48 volts used with XLR connectors only have a current at about 10 milliampere. Enough to supply power to a little microphone.
The connector is bulky and of metal, and designed to be used inside. It's also expensive compared to other connectors.
There are a lot of cheaper, more suitable connectors, designed to carry power.
In various industries, colors are used to differentiate between various voltages so it's obvious whether you're working with high voltage, low voltage, etc. so you can determine the necessary precautions for whatever you're dealing with (and some will also make the connectors incompatible so you can't accidentally join high and low voltage sets of wiring). I'm not super familiar with the automotive side, but I believe they use orange for high voltage and light blue for 48v.
Molex and others may as well get behind this. EVs are driving all the content (as you can imagine, electric vehicles are way more profitable than IC not only because they have additional connectors but also because they tend to have more advanced in vehicle entertainment).
The other reality is that all of the Chinese OEMs will generally work with the companies like Molex, TE, Amphenol, etc just long enough to let them shoulder the R&D cost and then reverse engineer and vertically integrate the part in their supply chain.
If there is a chance to leverage their scale and supply chain to compete where there is known demand, it’s worth it to be early in and then be able to help OEMs customize the reference designs as needed.
Judging just by the title (and without noticing the source), I was hoping that this will be about standardisation of the vehicle metrics data via OEM sources. Last year I worked on a system that collects this data, and currently each OEM has a different method (sometimes several, for different message types) it can use to share it with the wider world.
They would have to 100% open this up and give it to standards bodies, otherwise it isn't a standard. The conformity tests and testing equipment designs and protocols should be freely available.
Usually they create their own design so maybe having an open standard would allow you to do contract orders with any plastic injector that has the molds.
Anyone really. If you look at the quick connect fittings commonly found on German cars they're all built to a standard (VDA not DIN in this case) but built by the NORMA Group or Parker.
There are already MANY standard types of connectors that automakers don't use consistently, why add another one to the mix? What does this offer that Deutsch or Weatherpak don't?
Besides that, I have no respect for Tesla. They can't engineer their way out of a paper bag, they are hostile to both the customer and the rest of the industry, and notoriously so in terms of repairability--why would I believe that now they suddenly care about designing a better, more universal connector? They don't even make repair parts available to the consumer!
For those reasons and many more, the absolute LAST thing I would ever do as an engineer is to buy into a standard set by Tesla, or any other company run by Elon Musk.
NACS is finally standardized as SAE J3400 with other vendors shipping those cars in the United States next year, and now they're introducing a new connector with no clear advantage?
china has the most electric cars, the largest manufacturers, and the most advanced battery production on the planet. their experience with electric vehicles and charging would be a valuable leap forward.
The GB/T is for charging and not in car connections. Tesla already has an arguably better connector NACS or J3400 now.
As for China having the most electric cars on the planet. I don't feel that makes them the experts. China tends to steal / copy technology from other countries and has little innovation them self from my view point. They have the most EV's from heavy government subsidies. Tons of cars in graveyards over there.
Using one kind of unkeyed connector in a car may be a bad idea. Things can be plugged in wrong during repairs. There's a lot to be said for making connectors not fit where they shouldn't. Especially in automotive, where many connectors are plugged in blind, by feel. This simplifies manufacturing at the cost of repair.
If it can be plugged in wrong, it will be plugged in wrong. AAA put a battery in backwards in my Jeep once, and most of the vehicle electronics had to be replaced.