Here see if this will help you out,
Attachment 54591
When you open this PDF it will be hard to read , look at the top of your display see the words Adobe Reader. Look for the word VIEW select that and rotate the image, you can also change the magnification
This link has a cleaner wiring diagram
1951 Chevrolet- Wiring Diagrams
To get the PDF from here look for the following on the page: To view and print a FREE large 1951 Chevy Wiring Diagram in PDF format CLICK HERE!
the file was to big to upload to this post..
NTFDAY is correct about three wires for the left side only don't forget about the right turn, so four is the grand total of wires to the rear.