molding your sides should have nothing to do with your dome light wiring.
most likely a fuse blew or the light burned out. also it may have a short. unscrew the housing, snap off the cover and first try and see if you have a short (move the light around). then check the fuse. you can find the fuse diagram of the celica here:
ecelica.com: celica fuse diagram if both of those come back negative, then i would replace the bulb (watch out--their different if you have a sunroof or don't have a sunroof, so make sure you get the right one).