How many feet of wire to get for a full rewire?

[Wood and Steel]

The wiring on my '51 Plymouth are pretty dang crunchy, and I think it's time for a rewire. I have the schematic with the correct gauges and colors, but I'm not sure how many feet of wire to get. I found a pdf that someone made for a B1B that had the lengths. Is there anything like that for an early 50's sedan? Would it be similar enough to the truck that I could just order some extra and call it good?

[Doug&Deb]

I’m not sure how easy it is to find the correct connectors. A pre made harness isn’t cheap but will make the job easier. Rhode Island Wiring and YNZ Wiring come to mind. Do you have a parts manual? I believe it calls out the gauge but I’m not sure about the length.

[Eneto-55]

3 hours ago, Doug&Deb said:

I’m not sure how easy it is to find the correct connectors. A pre made harness isn’t cheap but will make the job easier. Rhode Island Wiring and YNZ Wiring come to mind. Do you have a parts manual? I believe it calls out the gauge but I’m not sure about the length.

No, none of the wiring diagrams I have ever seen give any indication of the lengths of each wire.  I've been working on figuring that out for my P15, but the masking tape labels I put on back in 1980 got brittle and lots of them fell off.  Also, I had repaired some of the wires back then with wire my brother & I scavenged out of a 53 Plymouth, and now all of the wire covering is too brittle to trust it anymore.  I know that some think it's nonsense to be concerned with strand count, but the fewer strands used to make up a given gauge the more prone it will be to breaking due to vibration, etc., and also a lot more difficult to work with (in routing it in some confined areas).  And I've yet to see any manufacturer of replacement harnesses that give the strand counts for each gauge they use.  (But maybe I missed it for one or more of them, in their product descriptions.)

I actually have written up all of the lengths for each wire for the front part of the harness, but still have to label and pull the part that goes from under the dash back.  Also want to add wires for turn signals, back up lights, and maybe some other things as well.

[keithb7]

Consider upsizing your gauge. Especially to the headlights. Wouldn't hurt to get as many amps as you can out there and back.

Are you making your own harnesses? Its fun, and very satisfying.

Edited March 5, 2022 by keithb7

[allbizz49]

Why not just remove the old wiring, lay it out and measure to see what you need?

[Eneto-55]

14 hours ago, allbizz49 said:

Why not just remove the old wiring, lay it out and measure to see what you need?

If you were in any way responding to my previous comments, that's more or less what I did, but I also wanted to preserve the relationships between each wire - how to get them lined up one to another as they were originally.  By marking various "reference points" I have been able to take the measurements without loosing the arrangement of each wire - that is. it still looks like a wiring harness, not just a bunch of coiled up wires.  This was complicated for me by the fact that the masking tape markings I put on each wire when I disconnected them to remove the dash (back in 1980) have since dried up to the point of such brittleness that they fall off if I just touch them.  So I now don't know for sure which wires went where.  The wire insulator covers are also so faded that I cannot even tell what color they were.  

 

So the objective is to not only know how many feet are needed for each gauge, but for each combination of gauge and color.

 

(As far as the first part - preserving the knowledge of alignment of the different wires in the harness as a whole - I suppose one could also just string each wire one by one, then tie them all together at different spots, and then pull it all back out to do the binding.)

[allbizz49]

No, I was just suggesting a simple solution to the OPs question regarding wire length.