18ga pink should go to the coil, and can be traced back to the gas gauge.
10ga red should go to the solinoid terminal closest to the engine, and traces back to the ignition switch.
10ga black should go to the large center terminal on the solinoid, and traces back to the ammeter gauge.

This is how it is on my '53 and what it shows in the manual.


I.I. #3174