It looks like water got in the rear running board light socket and the brass contacts have now dissolved and the bulb and socket needs to be replaced. The connector / light socket part number stamped on it says KOITO E9-1, but the dealer cannot find the replacement part. Does anybody know what the Toyota part number is for this, and it's associated bulb? Is there somewhere else where I can find this part? Have not had any luck on the Internet which is really surprising. Can post pictures if that helps. Thanks very much if you can help.