No W140 brake lights with ig key off? - PeachParts Mercedes-Benz Forum

oestek · #1 12-14-2010, 07:41 PM

This seems strange... the brake lights do not function in my '95 S500 with the ignition key off or out of the tumbler. I swear they used to. Am I losing it? Everything else works on the car, save for the flash-to-pass high beams, but I can't imagine that's related... any thoughts?

compu_85 · #2 12-14-2010, 08:17 PM

The brake lights on my W126 turn off with the key.

-J

Gilly · #3 12-14-2010, 08:43 PM

Standard European car, no brake lights with ignition off.

compu_85 · #4 12-14-2010, 09:58 PM

Do BMWs do this too? VW/Audi does not, though the horn is on the ignition switch like a Mercedes.

-J

oestek · #5 12-14-2010, 11:13 PM

Thanks guys. Glad to hear it's working as designed, but I'm a little disturbed it took me 7 years of ownership to notice it!

I do think they should light up without the car running, though.

Thanks again!

#6 12-14-2010, 11:28 PM

I don't think I've ever seen a car that's brake lights work without the key.

oestek · #7 12-14-2010, 11:33 PM

Quote:

Originally Posted by Craig

I don't think I've ever seen a car that's brake lights work without the key.

I think all American cars have brake lights that work with no key.

#8 12-14-2010, 11:38 PM

Quote:

Originally Posted by oestek

I think all American cars have brake lights that work with no key.

Interesting, it's been a while.

Ferdman · #9 12-15-2010, 06:33 AM

oestek, why would the brake lights need to function without the key in the accessory position or the engine running? Makes no sense to me, and apparently not to Daimler-Benz either.

lkchris · #10 12-15-2010, 12:09 PM

Quote:

Originally Posted by Ferdman

oestek, why would the brake lights need to function without the key in the accessory position or the engine running? Makes no sense to me, and apparently not to Daimler-Benz either.

Make that Bosch, as German car electrical systems are to standards set by Bosch.

oestek · #11 12-15-2010, 12:41 PM

I always thought it to be a safety feature. I imagine there would be a circumstance when the car would bot be running and it would be helpful to have visual that the brakes are applied, like during a crash cleanup, towing, etc. We restore American cars and the brake lights have always had hot power with no key function. Not a big deal, just something different in European cars I guess.

#12 12-15-2010, 08:15 PM

It's probably just cheaper to run hot power to the lights than to have them switched.

compu_85 · #13 12-15-2010, 08:30 PM

As I noted VW/Audi's have the brake lights active all the time.

MBeige · #14 12-15-2010, 10:44 PM

Quote:

Originally Posted by oestek

I think all American cars have brake lights that work with no key.

Most Japanese cars also do.

Same with the horn function, actually. For my MB's the key has to be in position 2 (engine running already, or prior to cranking) for the brake lights and the horn to work.

#15 12-16-2010, 02:55 AM

Quote:

Originally Posted by MBeige

Most Japanese cars also do.

Same with the horn function, actually. For my MB's the key has to be in position 2 (engine running already, or prior to cranking) for the brake lights and the horn to work.

Weird, I can't imagine why I would want my horn or brake lights to work with the key off.