Sidemarker bulbs keep burning out & lamp defective msg
10-24-2006, 01:58 PM
#1
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Sidemarker bulbs keep burning out & lamp defective msg
My 97 E420 burns new sidemarker bulbs WAY faster than it should. I also get "lamp defective" msg when i turn them on. is the car sending too high of current to the bulbs? is there a relay or a fuse somewhere. thanks for your help, I'd love to solve this problem myself instead of paying $$$ at the dealer..
10-29-2006, 10:34 PM
#3
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2005 C Wagon (No snickering please!)
There is a TSB about this. The alternator voltage is higher than the design voltage of the lamps. If your car has wedge base lamps you might also be using 196 lamps, which are lower wattage than the correct 5W lamps specified. Lamp number 168 would be a better choice. Mercedes solved the problem by installing a resistor inline with the bulb in the wiring harness. This limited the current to the lamp. There are harness adapters for some cars.
You can fix it yourself, get some low ohm resistors, and try them until the terminal voltage on the lamps does not exceed 12.2 volts. I would try 1, 2.2 and 3.3 ohms at 5 watts.
You can fix it yourself, get some low ohm resistors, and try them until the terminal voltage on the lamps does not exceed 12.2 volts. I would try 1, 2.2 and 3.3 ohms at 5 watts.
10-29-2006, 10:44 PM
#4
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There is a TSB about this. The alternator voltage is higher than the design voltage of the lamps. If your car has wedge base lamps you might also be using 196 lamps, which are lower wattage than the correct 5W lamps specified. Lamp number 168 would be a better choice. Mercedes solved the problem by installing a resistor inline with the bulb in the wiring harness. This limited the current to the lamp. There are harness adapters for some cars.
You can fix it yourself, get some low ohm resistors, and try them until the terminal voltage on the lamps does not exceed 12.2 volts. I would try 1, 2.2 and 3.3 ohms at 5 watts.
You can fix it yourself, get some low ohm resistors, and try them until the terminal voltage on the lamps does not exceed 12.2 volts. I would try 1, 2.2 and 3.3 ohms at 5 watts.
thanks for the info!! unfortunately i'm no electrical engineer and i have no clue how to do the resistor thingy. i could get some new bulbs though. so the new bulbs i should try are called "168"??
10-31-2006, 11:40 PM
#5
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update.. i got some 168 and 194 bulbs and put those in. still got f##King "lamp defective" messages.. 
strange though, I do NOT get the error message when i turn the lights on while the key is not in. what is different when the key is inserted??
strange though, I do NOT get the error message when i turn the lights on while the key is not in. what is different when the key is inserted??
