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BJ8 Wiring Diagram in "Ladder Logic"

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Bill Young

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It has never been easy to figure out how all the electrical components actually work using the "point to point" connection diagrams we have in our manuals. As a life long controls engineer (retired), I decided to see if I could create a usable "ladder logic" diagram presenting the functional logic of the electrical system. The attached diagram was developed for the 3000 MK III late BJ8. It is a 11 X 17 tabloid size. I have contacted Reid, our AHCA Chatter editor (and forum moderator) about publishing this diagram and future diagrams for the other Healey models in the Chatter. He suggested that I have a peer review of this diagram and see what the members of the forum think. I am open to corrections, suggestions, and comments as appropriate, to make this a resource for our Healey service and maintenance work. Being new to the forum, I found out that the file is to large to attach in the .pdf format, but it will attach in the .jpg format. I am not sure how this will work... so I an sending. Let me know if you would like a .pdf of this drawing.. Looking forward to your input .... Bill Young. sjahc.com
 

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Bill--

Without commenting on the accuracy of every element I think the diagram is a vast improvement on the original. I've got pencil/pen marks all over the diagram in my manual from past attempts to trace the route of a circuit and the circuitous routes of the various parallel lines make it hard to read and easy to commit an error.

I wish you luck with the project and I hope it comes to fruition--and for 100's as well as BJ8's.
 
Hi Bill,

Very nice work and I also agree that it is a vast improvement over the standard point-to-point approach.

As with Michael, I have extended the original harnesses to incorporate electrical changes in my BJ8 Phase 1. These modifications range from the implementation of a Crane electronic ignition to a full sound system and have been handled as extensions to the original harnesses to allow reasonably easy return to concourse level originality. Although I have worked with the original wiring diagram for many many years, the circuitry format you have chosen could go quite far toward allowing me, and others, to present the circuit logic as presently implemented in each Healey. It would be a big step forward to have a version that provided a baseline of the original factory wiring released with each model in a format that allows the application of notes and/or other modifications in order to create and present a contemporary depiction of the evolved electrical environment unique to each Healey.

I appreciate that what I am suggesting is more than a static depiction of a Healey model's electrical grid/logic and is more of a platform for presenting updated depictions for individual car. However, allowing versions of the diagram in a format that will accept notations would be a step forward. As my memory begins to falter or it becomes time for my Healey to be past to a new owner, I would like to make it easier for them to understand what they are working with.

Good Job,
Ray(64BJ8P1)
 
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As an aircraft mechanic I have always worked with DC (for the most part) wiring diagrams that are much more like what you have transcribed than like any but the older automotive diagrams. When I first cracked the books on my Healey, with no previous British car experience, I was slack jawed. Why would anyone do wiring this way, let alone have a circuit diagram that is unduly weird? Bravo and thank you much. I would love a nice crisp PDF if you would. Even though aircraft are not wired with color codes wires (again for the most part) and you have to read tiny printed numbers on them, the systems are still much easier to follow.
 
Send me your email and and I will send you a .pdf of the drawing.. BTW. my next drawing will be the BN2. (since I have a BN2 also. #229219) (for 51 years))

Bill
 
Geeeeze, now I really feel old. I designed conveyor and pallet loader schematics in that format for a company in Syracuse NY. That was back in the late 60's. How time goes by.
 
Bill,
I sent you a private message.
 
Ray

Thank you and all for the positive comments so far.

As I was developing the drawing, I could see that it was a challenge to re-create the original without showing many of the modifications we all of done throughout the years. I had changed to negative earth, added an ammeter, CB, provisions for driving lamps, Petronix, and several aux fuses to my BJ8.

I used the development software .. EDraw Max. https://www.edrawsoft.com. which is very affordable. I think $179.00 for a full supported license. It is loaded with standard symbols, however, I easily created most of the symbols in the drawing. The idea here is that I am willing to share these diagrams in the .eddx format, and if you have this software, you can open and add your modifications and make your own "car specific" wiring diagram. as you say so eloquently. .. "in order to create and present a contemporary depiction of the evolved electrical environment unique to each Healey". There is a little bit of a learning curve for this software, it seems to be based upon MS Word. Works on MAC and PC. It also has a whole lot more features which can be used for many other projects. What do you think about this idea?
 
dancrim said:
Geeeeze, now I really feel old. I designed conveyor and pallet loader schematics in that format for a company in Syracuse NY. That was back in the late 60's. How time goes by.
Click to expand...



Yes that is true the simpler Schematic Diagrams have been around for a long time.

On the other hand, they also created very highly detailed electrical drawings called Wiring Diagrams , this is a highly detailed roadmap of an electrical system.
 
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I like the drawing, good job! My bn1 is way simpler but did have the tough 2 relay OD controls that were well worn in my shop manual. After I switched it to the bn2 single relay system (no speed switch) it was much simpler. PS all electronic tech resources for these cars are invaluable, hardcopy is getting lost, tattered, and misplaced every day.
 
Bill Young said:
Ray

I used the development software .. EDraw Max. https://www.edrawsoft.com. which is very affordable. I think $179.00 for a full supported license. It is loaded with standard symbols, however, I easily created most of the symbols in the drawing. The idea here is that I am willing to share these diagrams in the .eddx format, and if you have this software, you can open and add your modifications and make your own "car specific" wiring diagram. as you say so eloquently. .. "in order to create and present a contemporary depiction of the evolved electrical environment unique to each Healey". There is a little bit of a learning curve for this software, it seems to be based upon MS Word. Works on MAC and PC. It also has a whole lot more features which can be used for many other projects. What do you think about this idea?
Click to expand...

Bill--

Aside from the fact that I would have no other use for the software and it would be $179.00 down the drain I, and probably a number of others, would not be inclined to learn how to use it if there were someone--you, for example--who for a reasonable fee could create such a diagram specific to my car. I don't know what your inclination to provide such a service would be and how much work is involved in customizing the product but I have a feeling you have a number of potential customers if you were so interested.
 
Ok let me play devils advocate here. Firstly I am not an electrical engineer or an engineer of any kind, but I can understand the original wiring diagrams fairly easily. The only issue with them is the scale and lack of colour used in the workshop manual. I created my own on a large sheet of paper using coloured markers and I find its pretty simply to follow and test circuits. I’m not sure the ‘engineers’ version is as simple to understand for a layman but I don’t doubt it’s an excellent piece of work and addition to the Healey data base.
 
DerekJ said:
Ok let me play devils advocate here. Firstly I am not an electrical engineer or an engineer of any kind, but I can understand the original wiring diagrams fairly easily. The only issue with them is the scale and lack of colour used in the workshop manual. I created my own on a large sheet of paper using coloured markers and I find its pretty simply to follow and test circuits. I’m not sure the ‘engineers’ version is as simple to understand for a layman but I don’t doubt it’s an excellent piece of work and addition to the Healey data base.
Click to expand...


The engineering version is what you have been using all along, simplicity is an engineering objective if possible.
 
I have to say I agree with DerekJ. I never had any problem with the schematics in the manual. To me, this 'ladder logic' isn't logical - probably a result of my lack of education. I much prefer seeing the spatial relationship/relative locations of components in order to trace issues (like a flow-chart). I too have made an enlarged photocopy from the manual and colored with hi-lighters for the wall in my shop.

However, I imagine that for anyone trained in this 'ladder logic', this would be a great addition to the arsenal.
 
Red--

Whether or not it is logical it certainly is legible.
 
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