Failed light bulb warning - W140
 

The blown bulb warning light on my '93 S500 comes on intermittantly when I have the lights on but all the bulbs are ok. Any ideas - I hate intermittant electrical gremlins!

TIA Andy

i had a loose bulb in a rear light cluster - cant remember what (? brake?)

go give 'em a wiggle - (sorry for the technical terms... ;) )

bulb fail light
 

I was getting the same indicator on my '92 500SEL and couldn't figure it out for quite awhile as all lights seem to have been working. I narrowed it down to a front indicator bulb, the age-old 1157 with multiple filaments. I do believe the car has a problem with multi-filament bulbs in this respect. My advice is to check those first, particularly the front turn-signals.
As a side-note, I intermittantly get a bulb-failure dash light on my '86 300E and have for years now....it just seems to come on every 6 months or so and last perhaps 2-3 days and then disappear for 6 more months...who knows!

Re: bulb fail light
 

Your taillight rails are causing this problem. They get loose with vibration and loose contact with ground, setting off your dash indicator.

The same vibration probably seats them back in place, and the indicator goes back off...weird. :rolleyes: