In Vibes, you either get two map lights built into the rear view mirror, or you get one that's part of the moonroof controls. (but not both) Seems like you're referring to it as "the" reading light, so I assume you mean the one built into the moonroof controls.I have looked at that thing, but not the light control part of it, and I don't know why it would be acting up for you. I do know that it is relatively easy to take out, if you want to just replace the thing with one from ebay or a junkyard. See steps 1 & 2 in
http://forums.genvibe.com/zero...61440You could take off the cover, hang the thing down from the headliner and leave it hooked up, press the button and see if any cause is visible, make sure the bulb is in there correctly (although it sounds like a switch problem) make sure the connector is on right, see if there is any foreign matter under the switch button, etcDon't know what to offer if instead you have the map lights in the rear view mirror, I haven't ever taken one of those apart, but replacing the mirror should be as easy as disconnecting the wire and then using a torx bit to loosen the screw where it mounts to the windshield, then slide it up off the part that is glued to the glass.I'd be surprised if parking the Vibe outside in the rain had anything to do with it, unless you had other problems as well (such as water dripping from the headliner )