Learn basic automotive wiring with Arduino components


I am starting a restoration project of an old car and want to learn basic, analogue (I guess!) automotive wiring. I have a basic theoretical knowledge of basic electricity and electronics but to feel confident enough to start meddling with the actual wiring in my car, I would like to practice where a mistake leads to less drastic consequences.

Therefore, I have the idea that I could try to replicate a basic automotive wiring system with Arduino components. Having a battery, a switch replicating the starter key, a starter circuit (where the output could be just a LED or something else replicating the starter engine moving), different lights (flashing turn indicators etc.), stuff wired outside of the starter circuit (that you would like to be able to use without having the car running), etc, etc.

First - do you think this is a viable idea?

And if so - any ideas of how I would do it, and which components I would need? For example, relays seems to be important in car wiring, and I would like to learn how they work.

I have not bought any Arduino kits yet. I understand I could do this with other basic electric components and save a few bucks but I like the concept of 'kits' like the Arduino starter kits.

Any input appreciated!

Hi Alec,
This is an interesting idea.

You need to learn some basic electricity, something about switches and sensors, something about current flow control like relays, something about actuators like door lock solenoids, various signal lights, wiper motors etc.

Good thing is all those parts are cheap at the junkyard or zero if you just take someone's junk car. THEN get the junkyard guys to take it after you remove all the taillights, door locks, instrument panel, wipers etc etc. Then you get to actually see all those things and how they really go into a real car. And you learn that everything that looks like some big important together invention is really just a bunch of PARTS.

See some of the info on ArduinoInfo.Info HERE:

That has stuff like Power Control with Arduino HERE:

Years ago I had some middle school kids take a Walmart plastic toy car and add LEDs, switches, headlights etc. and write code to make the controls and lights work (It did not run by itself). These days Arduino would make that interesting, especially if you have kids or work with young people.

Other: You need a decent multimeter. Because: "Electricity Is Invisible!".. But you can get a decent one for $10 like THIS:

See some Arduino Learning ideas HERE. Thousands of young people have used that kit or similar ones to start understanding microcomputers and sensors and actuators.

What make/model of car do you have?? Do you need to learn the bodywork/welding/painting stuff too?

Let us know what you end up doing!

DISCLAIMER: Mentioned stuff from my own shop... of course, but you can get this stuff on Amazon, Ebay etc etc. and Sparkfun and Adafruit have a lot of interesting devices to learn about.

but to feel confident enough to start meddling with the actual wiring in my car, I would like to practice where a mistake leads to less drastic consequences.

I have succesfully fiddled with car wiring in the past and I'm not sure what useful knowledge you will get with an Arduino.

The potential problems with any sort of wiring are fairly basic

  • a short circuit leading to a blown fuse or a burnt out wire if there is no fuse.
  • reversed polarity - again maybe a blown fuse - or destroyed elecronic components.
  • wrong connections - destroyed electronics?
  • an open circuit - something won't work.

All these can be explored with pencil and paper.

The problem is putting theory into practice and that requires the ability to read the vehicle wiring schematic and to identify components. I can't see how an Arduino can help with that.

Obviously some practical skills such the ability to crimp connectors, and perhaps to calculate the required wire size for a particular load are also required.

What areas are you not confident with?


Other: You need a decent multimeter. Because: "Electricity Is Invisible!".. But you can get a decent one for $10 like THIS:

While a totally agree with you about the importance of a multimeter, don't know if that one is a "decent one". I strongly suggest to limit the use of such multimeter to ONLY experimenting with Arduino, and ABSOLUTELY don't play with mains or automotive with it, 'cause could be quite dangerous, especially for a newby!

P.S. : I own one similar (DT9205A), so I know what I'm talking about!

Ciao, Ale.

As long as you don't short things out or play with the sparkplugs, there is nothing "dangerous" about automotive wiring and any DMM will do.

I think a basic circuit lab would be just as good as an arduino:

If you refer to the voltage, totally agree. But automotive has always a battery capable of sourcing a hundred of amps, what's going to happen if you forget your leads on 20A (unfused!!) input and try to measuring the voltage battery? No nice experience, I guess...

Ciao, Ale.

You destroy a meter and maybe weld a lead to the battery. Exciting yes, but not that dangerous to you.

How are you with cars in general? and how old a car are we talking about? what features does it have as the more its got the more complicated its going to get but you will have a wiring diagram for the car so will tell you everything you need to know.

In addition to Robin2's list of potential problems, with automotive you can include bad earth connections causing feedback.

This feedback can create some rather difficult to define problems.

As an example, one that instantly comes to mind was when a customer would park his car.

If he parked and then operated the handbrake, the engine would turn off, so long as his foot was off the brake pedal.

If he parked the car with his foot on the brake, the engine would not turn off.

Cause was a feedback circuit from a bad earth connection on the brake lights.

Another "rather dangerous" practice to be avoided is sparks around freshly charged batteries, disconnecting the positive terminal first in a negative earth system, working in and around live electrics wearing a watch, ring or other conductive materials. Burns from this type of thing can and do cause severe burns and at times, loss of fingers or ever ones sight.

Other than that, for learning automotive electrical, Google .......heaps of info out there with circuits, repair tips etc. etc. even utube...just keep an open mind as some can be more inexperienced than yourself.

There's really no 'replicating' analog 12v automobile circuitry.
When you build it, you've made one.

Older car circuitry is simple. Trying to throw a microcontroller into the mix is irrelevant to actually learning anything other than learning about microcontrollers. Different topics.

You could work on smaller analog circuits, but there's no reason to. Relays are about as complicated as old cars get, and you might as well have the hands-on time with the actual parts.

Just realized the OP is a John LeCarre fan.