First of all, i'd like to say, it's not necessary for you to pull back your sunroof lining in order to get to the bulbs. You can just take off the clear cover protecting the bulbs... the get to the map lights, just inclip the black housing around them as well. -easy access and clips all back together easily (i did this with success and no hassle)
This shows how it looks when you take it out of the box. The problem is the pins are too close together and they don't touch the 12v source in your dome light in order to complete the circuit.
This shows what you should do in order to complete the circuit. This is tried and true and will keep you from getting frustrated at your lights. ^__^ Shown in green is if you feel like taking an extra step, you actually wrap the pin around the side for an even more secure fitting. I had to do this because i have subs in my car and i'm afraid i'll end up rattling the connection loose.
And always check for the circuit! (third picture shown below)
ALSO! If for some reason you tried troubleshooting before with no results and you think your other map lights stopped working, try pulling the fuse (see your fuse box layout) and plugging it back in [you should hear electronics reset in the car]. Then hit the button - should work
tags for post: dome light, won't light up, problems, polarity, LED install, tutorial,