Just bought a 1991 Ranger and the third brake light isn't working. anyone know what bulbs/fuse I should get to try and get it going?

EDIT: The third light over my bed isn't red, it's white and I read that third brake lights weren't mandatory in trucks till 94. is mine even a third brake light or is it just a cargo light?

 

Welcome to the forum

Same fuse as rear brake lights, so if they are working then not a fuse issue

The cab mounted brake light housing is a known leak point so just a heads up when replacing the bulb

I don't know the bulb number