lars

My 03 coupe suddenly developed a problem with its turn signals.

Symptoms: Left indicator would stop flashing after three blinks, but only about half the time. Right indicator would sometimes turn on the left turn signal (not nice!) or would other times cause the signals to flip between their left and right turn states (a few lefts, then a few rights, then…). A good incentive to go straight, one could say.

Solution: Dealer installed updated front turn signal bulb sockets. I didn’t get a copy of the work order, so no part numbers. As improbable as it sounds, this appears to have fixed the problem. There has been no recurrence in a week.

Edit: The combination turn signal switch was also replaced (see below).

Two visits (one to diagnose, one to install parts). Two good loaners, an 03 C240 and an 03 ML350, demonstrated to me once again how nice a car the coupe is. Free car washes, but not a donut in sight. I can see I might have to move to SoCal.

Dealer had an S600 twin turbo in the showroom. Awesome sound and finish: stitched leather dashboard top, suede headliner, reclining rear seat, a REST system that blows air much faster than my car does, and lots of wood.

tifosiv122

Glad to hear its fixed...may I ask how many accidents you caused? :p

Erik

vyse

Where in Canada are you?? I don't notice free car washes

Jens C320

My 2003 C320 Touring had blinker problems as well. Sometimes the blinker would illuminate continuously instead of blinking...also it would vary the blinking speed and sometimes it just didn't work. But crossing left and right is something new to me, sounds comical from my end but I can see that being a huge problem in traffic!

antonio

can you please post the new part number for the updated turn bulb sockets. thanks.

lars

OK, I got a copy of the work order, and I can see that the main combination switch was also replaced. This switch is a more probable cause of the problem than the lamp sockets, in my view. Here are the part numbers:

203-826-02-82 lamp socket (2)
000-545-78-80 gasket (2)
000-545-23-10 combination switch

aborwick

I just had a turn signal problem; the left front headlamp turn signal went out and I got a warning message on my dash display screen. The turn signal blinker also blinked fast. I still had turn signals at the rear of the car at at the front driver's side mirror, so I felt the car was safe to drive. I took the car into the dealer service and told my service representative that the "turn signal bulb" was out and expressed puzzlement that a bulb could go bad on a car barely 14 months old. He explained that it was not the bulb at all, but a defective wiring harness that caused the bulb to malfunction and that a lot of cars were coming into the dealer with that problem. The dealer replaced the wiring harnesses on both the right and front headlamps.

Matt230K

The reason that the turn signal blinks fast is a built-in feature that all cars have (or at least most). It is there to let you know that you have a turn signal bulb out. This isn't necessary in an MB because the computer will tell you when the bulb is out and which one. But I guess they still have the fast blinkers too.

lars

Fast flashing can also be caused by a dirty light socket or a partial ground or, I guess, a wiring harness that mimics one of these conditions.