Mercedes Light Defect

[bluebirdino]

hi i need some advice for an old R plate mercedes , the brake light on driver side isnt working , although the tail light on same side is . the bulb has been changed and there is a "lamp defect" display on dashboard . any ideas what the problem could be ? thanks .

[bhg481]

Two suggestions:

1) try another bulb, just in case the new one is faulty.

2) Are you sure you have the bulb the right way round. Stop/tail-light bulbs have offset pins and are only supposed to go in one way but brute force can prevail and you frequently see cars with one tail-light brighter than the other.

[Hymie]

A possible cause is a poor connection in the earth/return wire to the lamp cluster. A brake light is more powerful than a tail light and as such the additional current flowing causes too great voltage across the earth/return path for the bulb to illuminate correctly.

Take a close look at the earthing arrangement – often corrosion at the chassis connection is to blame on older vehicles.

[TWR]

Where the bulb fits into the holder ( With the Ign off) clean the connecting points within the holder also the bulb and try.