12v, and wired to the headlamp switch , crank the headlamp dimmer around till it clicks; headlights not on; then re-check the lamp switches.
Also on there own chassis fuse " dome lights".
One of the things I intend to change on my coach. DW doesn't like the lamps , and I don't like the way they operate.
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.