Q:
A: If you want to fix it yourself, remove the tail lamp assembly from inside the trunk. If you're slow, don't drain the battery while the trunk light is on. Locate the bulb that is for the turn signal. You will see that it is also a tail lamp, and has two filaments. The brighter one, for turn signal is probably burned out. You pull it straight out and replace it the opposite way. 3157 is the number of a replacement. Sometimes on this car, it is just moisture/humidity at the contacts. That's not funny. It means scraping the terminals or connector, spraying or cleaning with alcohol and a swab, and tightening the connection for the future, without breaking it - a costly slip.