A pair of relays make it all happen
The diagram is a simple schematic on how to set up your headlights so that both high and low beams get a full 12 volts. This results in brighter lights and better night vision.
The original wires for the headlamps are tapped at the red dots and the new feeds come from the relays at the blue dots. The relays should be a units with a capacity for 30 amps or more.
4 pin relays are pretty common and a few of the choices are
Bosch 0332014157
Four seasons 35989
Sorenson 41-5118
GM 15515693
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