Rear left turn signal went out -- replaced bulb, still no good. Checked fuses, etc. Just put it back together to "get to it later." Then the right one ALSO went out within a week. Now I began to suspect the turn signal switch in the steering column -- and not looking forward to fixing THAT... but then, just for fun, I opened up the right turn lamp and noticed that the socket connecter (metal contact) itself was black and charred... so I opened up the left one... same thing. The rest of both lamp holders were completely clean -- and I live in Phoenix so there's no salt problem or excessive moisture or anything. I used sandpaper to clean up the contacts and everything works! Going to get two new sockets, but lamps are working again for now!