T660 can visor lights not working

[Chamberpains]

I'm not sure which one the visor light is on but Moose is right it has its own switch. Lamps and LMP (lamp) are also light control fuses.

While your in there, now might be a good time to pull everything in there and replace it. All the relays, breakers and fuses. I did this with mine and in the process I found relays that were corroded, fuse tarnished and breakers that were obviously really old and both corroded and tarnished. I imagine I saved myself a good bit of future electrical problems by doing this.