I recently scanned and cleaned up wiring diagrams from 1949, 1951, and 1953.
The 1949 and 51 are from original manuals. The 1953 diagram from a recent reprint sold as 1947-1954**
They can be found in this album. https://goo.gl/photos/H26qPfBHb7eS15698

The 1949 seems to use different color codes from the later trucks. Wire colors are on a separate page. This has more fuses in the fuse block than the later harness.

1951 info (all on one page, easy to read) differs slightly from the 49 diagram. The 51 diagram is fully included on the 1953 diagram with some other options then available.

I've noted in dark red on each diagram the printing date.

Don't overlook the COE diagrams because they include turn signals and trailer light harness wire colors and connections that could be useful to include in original fashion on your small trucks.

Grigg

** More info on the misleading 1947-1954 reprint , it is actually a 1953 manual and does/may not accurately reflect all years in all aspects, early wiring color codes for example.

Last edited by Grigg; 07/14/2016 2:18 PM. Reason: more info
•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
---All pictures---
"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-