The Ford Barn

koates · 08-02-2025, 09:04 PM

Well I have been an auto electrician for sixty plus years and never heard of or come across a dimmer or dipper switch that brings on both high and low filaments when set for the high beam position. To clarify the switch places power to either low beam OR high beam. That is a standard set up for all makes and models of vehicles since the 1920s. There are some exceptions in the early days but not in the 1940s. You need to get that switch out from where it is mounted and test it . I have come across some sealed beam units and bulbs where the filaments themselves were touching together. A wiring fault is not out of the question, but it would likely cause both filaments to come on in both switch positions. Regards, Kevin.

08-02-2025, 09:04 PM	#13
koates Senior Member Join Date: May 2010 Location: Melbourne Australia. Posts: 2,185	Re: 1941 headlight dimmer switch wiring Well I have been an auto electrician for sixty plus years and never heard of or come across a dimmer or dipper switch that brings on both high and low filaments when set for the high beam position. To clarify the switch places power to either low beam OR high beam. That is a standard set up for all makes and models of vehicles since the 1920s. There are some exceptions in the early days but not in the 1940s. You need to get that switch out from where it is mounted and test it . I have come across some sealed beam units and bulbs where the filaments themselves were touching together. A wiring fault is not out of the question, but it would likely cause both filaments to come on in both switch positions. Regards, Kevin.