How to Troubleshoot a 1989 Mercedes Benz 190E Turn Signal

1. Turn off the 190E's engine and open the hood.
2. Remove the retaining screw above the headlamp. Pull on the connector at the rear of the headlamp assembly. If the connector is loose or not connected, secure it to the assembly by firmly plugging it in.
3. Twist counterclockwise the bulb socket numbered '1.' This is the turn signal bulb. Push the bulb into the socket to remove it and replace it with a new 1156 NA bulb. Place the socket back into the assembly and rotate it clockwise to secure it. If the turn signals are still malfunctioning, the problem may be with the turn signal fuse. Close the hood.
4. Open the fuse box cover on the driver's side of the instrument panel. Use a screwdriver to remove the fastener on the cover. Locate the fuses labeled 'R HEAD LMP' and 'L HEAD LMP.' These are the right and left headlamp fuses. If the metal piece inside either fuse is broken, it will have to be replaced.
5. Pull the fuse out and replace it with a new 15A fuse. Replace the cover on the fuse box and close the door.