For those who want to learn about locomotive electrical systems, or teach the staff and volunteers at their museum about electrical print reading and troubleshooting, there is a convenient and useful set of booklets called “Tracing Physical Schematic Wiring Diagrams”, produced over a span of several decades by EMD. The booklets are specifically about locomotive systems, but do have some relevance to their other product lines.

The series was introduced in 1952 during the production of the GP7 and F7, and the books most useful to museums are those extending up through the 1970’s. Each time the book was reprinted it was brought up to date to reflect changes in the design of the electrical schematic prints and the new equipment in the locomotive product line. The terminology and symbol charts are also generally applicable to EMD power generating units, oil drilling units, and marine engine control panels in the same time period.

Here is a general description of the additions and the changes through the 6th edition in 1979:

1st Edition – Oct. 52 – Introduces schematic tracing with sample circuits from the 1952 locomotive line.

2nd Edition – Oct. 63 – Adds coverage of parts lists and adds zone layout of electrical schematics.

3rd Edition – Aug. 66 – Adds circuits applicable to the 1966 EMD locomotive product line.

4th Edition – Mar. 71 – Adds modules as used in DDA40X, preliminary to Dash-2 controls.

5th Edition – May. 74 – Adds full coverage of the Dash-2 modules and control system.

6th Edition – Apr. 79 – Adds coverage of the “Super Series” 50-series modules and control system.

For those looking to set up any teaching program on EMD locomotive print reading for a museum, the contents of the October 1952 edition and the May 1974 edition used together will provide a full range of coverage for most of the EMD products currently in railroad museums or operating on tourist railroads.

These booklets are no longer in print from EMD and the best source for them is eBay or document sellers at train shows. They show up very frequently on eBay.

There is an Alco-GE equivalent to these booklets called "Schematic Connection Diagram", publication number IS805. It covers a very similar scope to the EMD booklets.

Disclaimer: This is offered for information only, for those who may be interested in teaching or learning about this subject. I have no commercial interest in this.

PC

Thanks for the very useful information.

Is there a source for as-built wiring diagrams for specific locomotives? I am looking for:
Wabash 110 SW1
Great Northern 558 SD7

You can try writing EMD, 9301 West 55th Street, La Grange, IL 60525.

PC

While this does not specifically match your Wabash 110, N&WHS has one for an SW1

https://www.nwhs.org/archivesdb/detail.php?ID=127083

And in the back of the archives, there are quite literally a quarter ton of other drawings not cataloged as of yet, as we only have limited volunteers.

Best
Ken Miller

There is also a training slide set in the Heritage Rail Alliance (HRA) online technical library that presents the SW-1 electrical control system as individual circuits.

PC