I'm doing a boost gauge install on my 300d w124. I plan on making a DIY article (have pictures!)

I'm stuck - I want to make the gauge light up when I turn the headlight switch to the headlamp on position.


Theirs a slew of wires leading to the back of the switch. Anyone have any schematics or anything for these cars?

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-1983 VW Rabbit LS Diesel (5speed, VNT/Giles build)