Bob
One “tool” I found a game changer was to make a platform to lay on while working on all the under the dash tasks. It sure helped my old back. The platform is a piece of plywood about 40 inches long and about 12 inches wide, custom cut to fit between the seat pedestal and toe board sheet metal. The board lays flat on the floor board and sticks outside the cab about 20 inches and is supported on the outside by 2 legs. It helped to add a thin “mattress” on the platform for added comfort. Unfortunately, I apparently didn’t shoot a photo of the one I made.

As for the wiring. I experienced a similar problem to yours, except the new harness was of unknown origin. It came in a bag without any instructions, that along all the other parts and pieces of my project. As the others have urged and I agree, the ohm meter is your friend.

It helped to lay out the whole harness on a work bench and do as others suggested to trace each wire using the ohm meter. The
wiring diagram in the ‘46 Chevy Truck Shop Manual provided helpful guidance in deciphering wire application, such as head and tail lighting, horn etc. and routing.

Last edited by 46Sparky; 02/16/2024 3:22 PM.