S4 Wiring diagram in spreadsheet form

[msd1107]

Well, my car is back from the paint shop finally. I looked inside and saw all these wires wriggling around and thought oh dear, how am I going to make this right?

I had never had an electrical problem before, but was hesitant about trying to patch things back together, especially with 40 year old wiring harnesses, wires, connectors, etc.

So I naively figured I would rewire it. Went down to Kinkos and had the wiring diagram in the workshop manual blown up. At least I could see things.

But I got tired tracing wires, and getting crossed up! There must be a better way, says I in a burst of enthusiasm.

How to recast it? Being both a geek and a gearhead, I thought of a computer solution. Well, I thought about Access, but that doesn't seem to be a good choice.

A Word document could be good, since it is all text.

But I finally decided on Excel. Easy formatting, and the data can be exported in a form with which a circuit design program might be able to start.

So I am going to try to attach the spreadsheet to this post. It is a simple spreadsheet that is all text, no formulas or macros. Landscape orientation, two pages wide. The left page has each part, the Lotus P/N, source and destination parts, wire colors, etc. The right page is for comments. Print it out, tape it together and post it in the shop for reference.

Feel free to download it.

I would hope that other users would modify this to different Lotus models.

I have already been contacted to see if I would serve as a central repository for all the versions, and I have so volunteered. Please send me updates, corrections, new models, modifications, etc. I will try to figure out how to keep everything organized, updated, etc.

Have fun.

David
1968 36/7988

[Elanintheforest]

That's a great approach, David, and looks like it should form the definitive what-connects-to-what guide. When I get around to putting a new dash in my S4 I'll use and update it.
I am currently rebuilding a '74 Plus 2, and the factory diagrams varied considerably from what I found on the car. I have now compared 3 Plus 2s of the same period and found them to be identical...so the wiring diagram for the car is definately wrong.
I find when putting it all back together that a physical map of what connects to where is very useful. Often switches have several connectors on the back, which have no obvious differences and I can never figure which wire goes on which connector. So I've drawn up this picture, illustrating exactly what goes where. I'm also drawing out the physical connections under the bonnet and boot, and the loom 'bunch' connections, to try and make an idiot-proof map of wiring a Plus 2. The last one is work-in-progress. But here are a couple of pictures to see if it sparks any ideas for your work...pardon the pun
Mark

[msd1107]

Mark,

Great illustrations!

What program did you use to generate them?

While the dashboard is the most complex illustration, it would be useful and complete to have comparable illustrations for the rear, the front, the cabin, and the underhood ancillaries like the coil, starter solenoid etc.

It would be nice to use the output of one program as input to the other, and vice versa, possibly using some kind of translator, so that we could get both a textual output and a visual output.

I hope we have enough volunteers to create this for all the models, even though there may be subtle differences during various production runs. I doubt that Lotus ever saw the need for this forty years downstream.

And also to show how to add various and sundry "improvements".

David
1968 36/7988

[M100]

There is no need for any spreadsheets or diagrams, you just need spaghetti knitting lessons

[Elanintheforest]

It's just Powerpoint, David. I started using Visio which is a lot more friendly for drawing these sort of things, but not many folks use that, or CoralDraw or the various CAD systems.

Have you seen in the LotusElan.net Library>Technical Tips>Electrical there is an S4 wiring diagram in colour? It has been produced using a CAD tool, but there is also a bmp version. Very useful and a lot more clear than the original. I'll have a play over the holidays and see if that can be usefully imported to Powerpoint for further anotation.

I will be completing the front (under hood with lights, spots, horn, ignition, fan etc.) and under boot / trunk schematics as well as the interior. The car is down to the bare shell at the moment, literally without a single component attached, so I have no choice!

I think that if we stick to the standard Lucus colour coding (and colour usage), combined with the Lotus component numbering, at least we'll have the common syntax to tie it all together at some time.

Mark

[msd1107]

Mark,

I knew I had seen that colour diagram before, just forgot where it was.

My next door neighbor has Visio (not an Lotus enthusiast though). I will try to take a look.

Very true about sticking to the standard colour coding conventions! That is what conventions are for. And there are several sources for proper colour coded wire in different amperage ratings.

There is a bit of a bother when using third party relays and such, since they tend to come with red, black, and white. You have to figure what wire in the wiring harness they connect to, and have to make the correspondence in the wiring diagram documentation.

I believe there are already at least two instances of that in the S4, at the instrument voltage regulator and the cigar lighter. The documentation has both colours specified on the wire so you get the idea.

David
1968 36/7988

[elansprint71]

"I think that if we stick to the standard Lucus colour coding (and colour usage), combined with the Lotus component numbering...."

If only Paul Matty had done the same with his replacement looms.
I put one in last year- wires missing, extra wires, wrong colours, no connectors, illogical colour changes at connections.....etc. I took it back and asked them to connect up the connection of the three pieces which I could not figure out, on their parts counter. Their two best electricians struggled and still had some left over- they said "it's always like this"!!!! Only because they don't tell their bloody supplier.

The AutoCAD diagram in the tech section is invaluable, blow it up to A2 size; I think there is only one wrong colour on it.

Cheers,
Pete.

[msd1107]

Pete,

That is very disconcerting. I am surprised that Paul Matty has not had the matter corrected.

Which makes doing the job yourself even more attractive. Order the right wire colours, crimper, soldering iron, multimeter, connectors and install it one wire at a time. That way you know it is right, and right sized. And it gives you a leg up on making modifications.

David
1968 36/7988

[poiuyt]

Great Excel file. I have some questions on the color code (see ???). Also, let me know if I'm wrong with the others.

G=Green
B=Black
R=Red
W=White
Y=Yellow
GR = Green Red???
GW - Green White???
U = ???
N = ???
BR = Black Red
P=Purple

Thanks,

Steve B
1969 S4 DHC

[msd1107]

Hi Steve,

The good thing is that was an industry standard colour code.

There are many links on the web that explain them, some in black and white, and some in colour.

Google "Lucas wire color codes" for a selection of links. I think that some of our postings also had links. In any case, here is a reasonable link:

http://www.mgexperience.net/article/lucas-colours.html

Yiour guesses are good. U is blUe. brown is browN. Go figure!

David
1968 36/7988