Coincidentally, just last week I finally removed my center console and, in addition to finding the final member (hopefully) of the mummy mouse family - noticed that very large red/black wire wound around the main wiring harness headed towards the rear of the car. I followed it to the PD switch and, like you, cannot figure out why the heavy gauge. All I can think is that, since they had to wrap it around so many times to shorten it, means they had a stock of extra large, extra long wires with pre-installed spade ends from some other project, and wanted to use them up?
Anyway, I too, was thinking of re-purposing it. My original inductive tach has been erratic/dead and I happen to have a nice ex-MGB 7K tach that is the later, RVC type. I was not confident that the well-known capacitor fix would cure my original unit, so was trying to figure out how to get a new wire from the RVC unit to the coil - and the idea of using this big wire to do the job seemed like the answer. Fortunately, however, the new capacitor completely cured my original tach!
Ron
