Round back to square back alt

I can only speculate why Chrysler made the decision to use 12 gage wire. Presumably its a balance between ease of assembly, costs of materials, and acceptable performance. For example on the factory diagrams of this era we see the standard field wire for A-bdies was 18 gage vs 16 ga for B-bodies. Why? Was it because the wire run was shorter? Or perceived lower needs ? or just because they could get away with it to save weight and money on the smaller cars?

One thing I always like to point out is the headlights are a relatively big load, and can be running for hours. Additionally almost any replacement headlight from the last 30 years draws more power than the original 6012 sealed beams. Installing a relay circuit for the headlights not only gets power to the lamps with higher voltage, it means that alternator output wire never will see that electric load.

Alternator output vs input.
Field current draw off or on the vehicle. Post #9
https://www.forabodiesonly.com/mopa...ternator-on-69-valiant.545220/post-1974380959
Some info on alternator output measurements
https://www.forabodiesonly.com/mopa...40-swinger-non-a-c-car.545949/post-1974396063
Pulley ratio as well as the stator and rotor windings can really effect what can produced when the engine is idling at 500 or 600 rpm.