Wiring Diagram software please

Can anyone recommend a program for drawing/ designing car wiring diagrams please. Ease of use, ability to automatically link across multiple pages, all that sort of stuff.

I would be interested to hear of your success with using one of these programs if they exist.



Gulf GT40
Lifetime Supporter
I have Altium and it is pretty good but very expensive. They used to have a FREE version of the old DOS version called Protel PCB but it may be old and difficult to run on windoze. Just really ends up how much you want to spend to get hard core versions vs more limited.

Some lower cost version below.

You can look around and find some of the free or limited use software like Eagle PCB that you can use free with some limitations (Number or parts or pins, not sure). Look for some of the PCB cad software as some are free and can output DXF and other simple formats.

Just doing a search on google with 'Free schematic software' turns up some interesting links.

ExpressPCB - Free PCB layout and schematic software

This has some low cost shareware versions
Best free schematic capture downloads. Easy to use, professional quality electronic schematic capture software. A vector graphics diagramming tool for creating rich, informative diagrams.

Another one you is design cad


They have some low cost cad programs and are ok for fun stuff and reasonable priced.



Peter Delaney

GT40s Supporter
Hi Lee, I used the basic MS Visio to design / document my wiring (just using "basic shapes" & lines). I can't say that it is super-easy or "intelligent" for wiring diagrams / routing, but I used it because I was very familiar with the product from my past working life (doing computer room layouts, rack layouts, etc).

It is probably the smartest "drawing tool" around, & doesn't take long too learn at all. I haven't worked with the new Elec Visio add-ons, but some of them (like Electra 2005) look pretty good.

If you are interested, let me know & I'll post a copy of my wiring diagram.

Kind Regards,

Peter D.
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I use Express PCB And Schematic extensively for PCB design. Free, very easy to use. It is oriented to circuit board design but the Schematic program could be used for a car wiring diagram.

If you are looking for the basic functionality of Visio, check out Open Office Draw. Free, part of the Open Office Suite.

I think the website is OpenOffice.org: Home but I'm not sure. Great alternative to Micro$oft.
Thanks for all your suggestions. I looked into this a couple of years ago, and ended up using Express PCB, which I thought was pretty good. The only real problem was the time it takes because it is designed for 1 page designs, but the page is too small for a whole car.

I have attached the work I had done up to that point. It is nowhere near complete and probably has errors, but if you are also looking it gives an idea of what you can do with it.

I also tried PCB123 at around the same time without success.

I have now tried to use the demo of Visio, and also SmartDraw, but couldn't find anything remotely as sophisticated as ExpressPCB.

Peter D - I'd really appreciate your wiring overview please. PM sent.

AutoCAD Electrical and Altium look to be way over the top, jsut to be able to draw a car diagram.

Last car I did it by hand with pencil. 1 page for front bulkead forward, 1 for dashboard, 1 for middle/ rear of car, 1 page for the clips. (or something like that) I think I will have to do the same again unless anyone can come up with a more suitable program.

Anybody know what Haynes use for the diagrams in their manuals? Or are they supplied by the manufacturers running Altium/ Autocad?

Thanks again

Edit : attachment now added


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Gulf GT40
Lifetime Supporter
Lee, you might break down your car into a couple of 'pages' ie, the front end, engine, rear end, each on a page. Then just use the notion of a connector to tie the wires virtually together. It won't have electrically connectivity across the pages but at least you can use some software that was designed for circuits. Visio (and related), and some of the other software likely will not offer any electrical checks or connectivity. You will loose much of that if you do a multi-page approach on systems that don't support it, but at least you can wire things up.

I was going to do it in Altium since I have it, but ended up with a pencil and some graph paper, and of course an eraser ;-)

Some of the low cost cad programs may also be good, but I have not played with them for a long time. I think one of the old DesignCad or Turbo Cad add on packs was automotive electrical or electrical symbols but I have not used the stuff for years. Maybe look at some of the general cad/drafting packages they may have some stuff that helps.


With Visio, using the Electrical Engineering template, you can generate a netlist and therefore have connectivity.

Agree that Altium would be over the top for a one time build.

Neither Visio nor Altium address 3D modeling of the cable assemblies - this is most difficult and even expensive packages are very difficult.

I'm head of an engineering group where we just completed the design of a very very large power conversion system - thousands of interconnects (perhaps it's the most powerful "motor drive" ever designed). We developed a method using Altium schematic capture (normally for pwb's) and integrating that with a database (MS Access). We have been struggling with ProE to model the cable assembles and have found that for first article build we are doing it old school. The ProE models will be ultimately linked to the database. In the earlier phase of this program, all the wiring diagrams were done in Visio.

I think for the money and learning curve, Visio is tough to beat, plus it readily integrates into other documents.

Good Luck with your project Lee!
Depending on your budget, AutoCAD Electrical is one possibility, and I came across this paper that you might find interesting:
I've use AutoCAD Electrical eXtender which is fairly easy to use. It creates 2D drgs & 3D models which enables you to place components in their relative location in 3D space & it will then calculate point to point cabling routes with automatic dimensioning.

Probably the easiest to use is SmartDraw & electrical symbols are readily available for download.


Gulf GT40
Lifetime Supporter

The smartdraw program looks fun, I did the 7 day free trial download and looks like it has a nice simple auto symbol library and looks pretty easy to use. Don't know about multi page support but seems like a nice starter if you just want the symbols and connectivity. I would likely use this over a hard core cad pack if I just was after the diagrams and not the electrical connectivity that the Schematic software does. Lost of samples too in the download.