Universal electrics for old cars

[Sigi_H]

This will be a thread for developing principles of universal electrics for old cars.

In my eyes there are two options. Exactly original or really modern.

I decided for modern.

I already did some brainwork on this idea and will report it here in order to be pointet to my wrong thinkings and getting new ideas.

My main motives are:

Everybody should be able to make it.

Installation should be easy and straightforward

All parts should be easy to replace anywhere, even in foreign countries

Affordable parts and work

Ok, since I am an electronics engineer, I am not afraid about things like that. But on the other hand, thats why I don`t like to much electronics in cars, because I know: The best engineer is without a chance if he doesn`t know which software is in these small black beetles with lots of legs. On the other hand, I know that this will be easy to manage for everybody with little help.

Lets start.

1. The center of all should be an Microcontroller Arduino Mega 2560

Why?

Arduino programming is easy to learn even for beginners. The Mega 2560 has plenty of Input/Output-Pins in order to connect all dashboard and steering column switches. It can connect a RS485 Bus-System as well. Almost nothing has to be soldered. The Arduino is really cheap and can be hold as spare part. We can develop the code and different subroutines together.

2. Bus-System RS485

Why?

CAN is normally used in cars for bus systems. Very stable, but very difficult to program. RS485 Modbus is used in harsh environments not only in industry but also in domestic electrical systems. There are many components that are suitable for use in cars.

3. Power units front and rear.

Why?

I`d like to use identical power units (interchangeability) in front and rear of the car. It receives the RS485 commands from the Arduino and translates them to relay signals, which actuate the loads. All relays are standard automotive relays in order to get them all over the world.

A power unit consists of the relay box and electronics for receiving RS485. The RS485 receiver can have Inputs as well. I.e. for fuel tank capacity.

The relay box can be something like that

The receicer electronics can be something like that to be placed in the relay box

4. Instruments are realiced with a Madman

Why

Everybody can decide individually, which instruments to use. The Madman can be completely separate from all the other cabeling and shows many of parameters, including a alarm systen, when any parameter is out of the programable window.

 

 

All these ideas end up in the idea to use as less cables and connectors as possible. The connectors in car electrics are mostly only used for easy manufacturing in the industry, but will never be opened again in the live of the car. My idea is to save them all and solder all the loads directly to the small harnesses. I`d like to leave the cables a bit longer, for beeing able to cut them if necessary and resolder them. This will be a lot cheaper and saver than tons of connectors which will never be opened again.

The relay boxes with fuses will save a lot of cabeling and connecting. There will be no more central fuse box, but only large main fuses on the battery to connect the power boxes and automotive fuses for each relay in the power boxes. Keep in mind, a fuse does never protect the load, but the cabeling. The load is normaly gone anyway, when the fuse blows.

Cableing will therefore be reduced to a power line to front and rear and a Bus line to front and rear. Small harnesses will connect the power boxes to the loads.

Feel free to share your ideas and suggestions

 

 

Edited December 3, 2023 by Sigi_H

[hurbie]

i'm not a fan of Can bus technology (way to many faults/hick-ups , even in a OEM envirement) , bit this seems like a decent aproach .

can you make a drawing how the system looks like when in the car ?

 

 

[Sigi_H]

Thats why I prefer RS485 over CAN

I try to make drawings, but its a bit to early. So i apply to the imagination of everybody 😁

main goal is to have an overview to all by yourself and use a lot less cableing

 

Edited December 3, 2023 by Sigi_H

[Snagger]

I can’t see myself ever retrofitting such a system in my cars, but it’s great to have the information laid out for those of us who don’t understand how to design or programme electronics in order to give us the option.  I like your approach of eliminating connectors where feasible, as long as that doesn’t interfere with the normal reparability of our vehicles - there is a lot to be said for being able to quickly unplug the electrics for a front wing, for example, so that it can be removed with a minimum of complication or effort.

[Blanco]

Watching with interest, ... this is outside my comfort zone but could be very useful.

[Sigi_H]

I even would connect the front wings without connectors. Better to have a tiny loop in the cableing in order to cut it easy and the cables still remain long enough to solder them. On the other hand, you still can attach connectors in that case, if you find them necessary

 

[Sigi_H]

Another option could be a really good anti-theft method.

The Arduino can easily be expanded with GPS and even GSM, That means, it can send coordinates via mobile net. It can ask for a special code to start or activate the electrics. It can stop after a time, when there was the wrong code. No limitations. Want to have a special sequence of switches to start? Everything is possible and individual. For example: Activate the Ignition key. Then activate indicator left (no signal is turned on), then indicator right, then push the horn button (without horn signal) to start and voila' ... brrrrrrrrrr ... 😁

 

 

Edited December 3, 2023 by Sigi_H

[Arjan]

Very interesting so please keep it coming.

However, there always is one.....

A major problem with all the conversions is legality....

I have left only a few LR's and 1 could e a god candidate for an E-motor conversion. 

But one can't do it DIY here as only at the time of writing 2 companies can do this. And the amount of €€€  involved make it a big no go.

Not to mention us mere mortals living out in the deep dark Auvergne where 3 phase is getting rare and solar panels can't be integrated into the grid..

[Peaklander]

3 hours ago, Sigi_H said:

RS485 Modbus is used in harsh environments not only in industry but also in domestic electrical systems.

I used Modbus in the 1980s - it was the proprietary network connection for Modicon PLCS. RS485 is I think is based on balanced pairs, extending the range of normal RS232. What I didn't know about is its use in domestic electrical systems. Have you an example?

[Bowie69]

1 hour ago, Sigi_H said:

The Arduino can easily be expanded with GPS and even GSM, That means, it can send coordinates via mobile net. It can ask for a special code to start or activate the electrics. It can stop after a time, when there was the wrong code. No limitations. Want to have a special sequence of switches to start? Everything is possible and individual. For example: Activate the Ignition key. Then activate indicator left (no signal is turned on), then indicator right, then push the horn button (without horn signal) to start and voila' ... brrrrrrrrrr ... 😁

 

This scares me, a lot, can you imagine the court case when your vehicle shuts off in the outside lane of the motorway?

By all means do lights, track stuff, do clever sequencing, but keep DIY electronics and software away from the vehicle controls.

[Sigi_H]

51 minutes ago, Peaklander said:

I used Modbus in the 1980s - it was the proprietary network connection for Modicon PLCS. RS485 is I think is based on balanced pairs, extending the range of normal RS232. What I didn't know about is its use in domestic electrical systems. Have you an example?

Look for Modbus RTU in the Internet. Many of the chinese RS485 Cards work with Modbus RTU

Edited December 3, 2023 by Sigi_H

[Sigi_H]

7 minutes ago, Bowie69 said:

This scares me, a lot, can you imagine the court case when your vehicle shuts off in the outside lane of the motorway?

By all means do lights, track stuff, do clever sequencing, but keep DIY electronics and software away from the vehicle controls.

To be honest, this doesn´t scare me at all, because I am always free to hardwire things, which are important for me. Electronics only scare me, when the software is proprietary and I have no clue, what it really does. For example phoning "home" 😉

[FridgeFreezer]

Interesting idea.

Not sure I'd choose Ardunio, and CanBus exists for exactly this application so odd that you'd avoid it.

[Sigi_H]

I thought about CAN,  but I couldnt find a spec to program it. My experience from industry is: RS485 is way good enough !! Look at the spec.

... and a lot easier to handle.

Especially for people who are not at home in electronics

[Sigi_H]

The mayor problem in automotive electronics is glitches from the sparks in the ignition system.

No problem with Diesel and not really from neighbor cars on the road.

Spec of RS485 is way enough and experience tells the same.

[Sigi_H]

Example.

I built some electronic ignitions for gasoline engines and never had problems. Have a look at the megasquirt project and find out, everything is easy to handle

[hurbie]

4 hours ago, Sigi_H said:

The mayor problem in automotive electronics is glitches from the sparks in the ignition system.

No problem with Diesel ......

mmm i work with Heavy Goods Vehicle's at a Dealer , and we see a lot off hick-ups with can signal's on trucks .... and they are all big diesels ....

[Bowie69]

Spark suppression is a pretty well understood science these days. 

[jeremy996]

As you will know I am into Morgans, MX5s and less fanatically, almost anything with an engine. There is almost no electronic logic in a pre-1990 Morgan, so parts availability and fit of alternatives are the only issues. For the Mk1 and Mk2 MX5 only the engine ECU is an issue, and the usual workaround is a motorsport ECU like Emerald (or MegaSquirt).

Where things get really difficult is obscure bits of electronic hardware and the underlying logic of the body systems. Tesla Roadsters and early Tesla Ss are being bricked by the failure of LCD screens with specific characteristics and specific obscure control chips. Although Tesla have open-sourced much of the early patents, they have not been forthcoming with the technical specification of older systems, citing "security" as the main issue.

Is there a standard way to collate data on what each widget does, what the dependencies are and the sub-systems design? (You can tell I'm an accountant and not a systems engineer).

[FridgeFreezer]

20 minutes ago, jeremy996 said:

Although Tesla have open-sourced much of the early patents, they have not been forthcoming with the technical specification of older systems, citing "security" as the main issue.

TBH this has been more a marketing stunt than anything, they've "open-sourced" stuff that was all out there anyway and tells you nothing useful / nothing that people couldn't have worked out by themselves.

[Sigi_H]

19 hours ago, Bowie69 said:

Spark suppression is a pretty well understood science these days. 

It is and therefore I am not affraid about a max 4 m long RS485

Put the Arduino in a metal case, coils on all inputs and most of the problems are solved. RS485 is shielded anyway

 

[Sigi_H]

I have to say, I was inspired by the german company Joost, who made something like that, but with completely self developed components and proprietary software. He stoped the project, because he is more into motorcycle electrics now, but he was kind enough to leave me a lot of documents.

He also used RS485 for the project.

https://www.elektronikbox.de/shop/index.php?main_page=index&language=en

Main differences are:

The power modules are completely electronic, no mechanical relays and components. No fuses, because self protecting highside switches.

The dashboard module is a self developed Microcontroller board, no Arduino.

Why Arduino and relays

The Arduino is a cheap and well testet microcontroller, which can be changed easily

Highside switches have a lot smaller volume and are more reliable and self protecting , but they are not interchangeable in foreign countries. Relays with fuses are.

My concept with RS485 receivers in a relay box is identical for front and rear, but the adress-switch, which separates the adresses tells the box, if it is front or rear.

[Sigi_H]

As I can see, enthusiasm is limited 😁

I can understand that, as electrics are not everyone's cup of tea. In any case, I will stick to my concept. I will describe the progress and invite everyone to add their two cents. The project will certainly take some time, because everything is working so far. However, I have often seen cable insulation crumble and the copper strands inside have oxidised black over long distances. That's why you can't even cut off a piece of cable and crimp a new connector

[Bowie69]

Thing is you're not really talking about electrics, it's much more electronics / microcontrollers, and while I have no fear of those things (see my LGT digi dash), I simply can't see the benefit of having that much electronics controlling everything in the car. 

For a LR or any other classic car replacing a crumbling loom with a universal or even an auto sparks pre made loom is not at all difficult and should allow you to do everything 99.9% of what people want. 

That said, it's the 0.1% that change the world and it's obviously up to everyone to do what they want with their vehicles, so very good luck and all

 

[Sigi_H]

May be, but aren´t electrics simply more cables than electronics?

The benefit of using the Arduino and power boxes is minimizing cableing and connectors with easy to learn programming. The overall system is indeed easier than bunches of cables.

The arduino is no rocket sience. In every ECU is more calculating power and most of us rely on it without thinking.

Lots of people underestimate themselfes.

But as I said, I can understand the fear 🫣

Lets see, what develops from the idea and thanks for the wishes.

Edited December 9, 2023 by Sigi_H