Just to confirm the statements above, after being sure that you have good ground connections, the single best thing you can do with your headlights is to install relays. This ensures that you will get the maximum voltage available to the light source and also reduce the stress on your wiring/light switch.
I have just fitted a vintage dual 6V relay and semi-sealed beams to my '41 Coupe. With slightly higher wattage Quartz Halogen bulbs the resulted performance is fantastic i.e. it's like driving a new car, no more dim yellow glow for me
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Here's a link to one the same as I used.
https://www.ebay.com/itm/NORS-Dual-H...item56bfd47d35