2002 Mercedes Benz SL500 V8 Two Wheel Drive Automatic 95000 miles
we have changed all the bulbs and checked all the connections. When the lights are off the brake lights work fine. When all the lights are on at night the right outside brake light is not as bright when the brakes are applied. Is this a short in the assembly?
If you have no warning in the cluster for bulb failure you may be actually seeing something other than a failed bulb. Often times when fog lamps are on you will notice that the left rear side has a light that stays on causing brighter illumination on the drivers side light assembly. This is your rear for lamp and can make the left brake light seem brighter than the right. This is a normal condition.
January, 24, 2009 AT 8:31 PM
Thank you guys. Actually there is a warning in the cluster that there is a bulb out. I've checked all the outside bulbs, all are working except for the right tail being dimmer than the rest. When the parking lights are on and the brake pedal is idle, should the outside bulbs on the tail be dim or bright? The inside bulbs on the tail get bright when ever the brake is depressed. As for the fog lamps affecting the rear tail to be brighter, is that a defect with the vehicle? I see that often with mercedes where the left tail is brighter than the other bulbs. I would not be too worried if the cluster did not have a warning or that my wife gets pulled over for a tail light being out. Please help.
January, 25, 2009 AT 10:41 AM
Here's the easiest way to identify the failed bulb. When you first turn on the car there should be no bulb failure. This should only come on when the car senses the bulb is failed. So after sarting the car start by pressing the brake pedal. If the bulb failure comes up you have a failed brake light. If the warning does not come on go to the next step. Next try your turn siganals. If the failure comes up after checking these it is one of the turn signals. Next turn on the parking lights. Again check for the failure light. Finally turn the headlights on. By trying to isolate the accesory bulb that is causing this warning you should have an easier time locating the bulb. Also don't forget to check the side marker lights as these will illumoinate the cluster bulb failure as well. As for the lighting in the rear. With a static brake pedal your outside lights should be illuminated. As for the fog lamps causing left illumination of the taillamp this is normal. It is the european rear fog lamp, keeps on side illuminated to help with identifying the car from the rear in the fog. On last thing, don't forget to check your 3rd brake light in the rear window as this will set the bulb failure light as well.