My light bulb warning lamps goes on when the brakes are activated on my 96 850. All of the brake bulbs work. What does this warning circuit look for when it triggers a warning? Does it look for voltage? Bulb wattage? Can it be triggered by a dirty/corroded socket where the lamp works, but cannot be seen by whatever this warning circuit is looking for? I ran into the same problem on my 87 BMW E30 when the bulbs were removed to clean the lamp base and I may not have but the bulbs back into the exact socket that they came from. Everything worked properly but, the lamp warning light triggered. Help??????

Thanks, Raybun

 

It is triggered by a un complete circuit or low load.. either you have leds in there or you have a bulb out.. check all your bulbs again

 

Sedan or Wagon ??

I know on my wagon there are two on each side and the high mount in the center (5).

If the sockets or bulbs are corroded it can raise the resistance and trip the warning light. You need to remove each bulb and check the socket and the condition of the bulb.

Why not add the vehicles basic into to your signature in the "User CP". That way we don't have to ask each time you post.
Year, model, sedan/wagon, engine size, turbo or NA, manual or auto.

Location is also handy as you never know when you might have someone near you who can physically give you a hand or a second set of eyes or a part you need or want. Just a thought.