I have done that with sealed beams before, low is always on when you pull the headlight switch on, when you hit the dimmer switch, it adds the high beam without killing low beam.

I just connected the hot and low beam wires at the dimmer switch.


Mike
1955 Chevy 6400 ex-flatbed (no bed now!) sold September 2023
In the Stovebolt Gallery
1958 Chevy 6400 flatbed W/dump
In the Stovebolt Gallery
1959 Chevy Suburban Owned for almost 20 years, Daily Driver -- sold May 2016
In the Stovebolt Gallery

Sufficient unto the day is the evil thereof