What is the logic behind the exclusive relationship between low beam and fog lamp?
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Joined: Nov 2009
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From: austin, texas, usa
2006 e320 cdi
What is the logic behind the exclusive relationship between low beam and fog lamp?
So, when you pull the knob to turn on the fog lamp, the low beam turns off. I don't understand, what if I am driving at night under a dense fog? I also have trouble figuring out where the rear fog lamp is - it's supposed to be on the driver side only ... nothing look obvious 
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Joined: Nov 2009
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From: austin, texas, usa
2006 e320 cdi
maybe a cluster command setting then, I don't know. not only when I turn on the fog lamp, the low beam turns off, when I switch from fog lamp back to the low beam, there is a moment, a gap .. feels forever, when the fog lamp is off, and the low beam has not yet turns back on, and it's pitch black ... very scary, man!
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Tesla Model S P100D
So, when you pull the knob to turn on the fog lamp, the low beam turns off. I don't understand, what if I am driving at night under a dense fog? I also have trouble figuring out where the rear fog lamp is - it's supposed to be on the driver side only ... nothing look obvious
What I find annoying about the fog light placement is that you can pull the know only in ON position and not the AUTO position, where I leave it. Given the headlamp switch is not illuminated at night (I am sorry but this is idiotic of MB) good luck trying to turn the fog lights on at night while driving in the dark.
I don;t see the point in turning on just the fog lights but I agree in that the fog lights should have been activated by a separate switch like most other cars I've owned.
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Thats incorrect information. 1) there is only a left rear fog light to assist cars in passing (on the left) during foggy weather, 2) the high beam and driving lights will not function at the same time to prevent blinding oncoming traffic. Correct, driving lights do not turn on using the "auto" setting...
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2008 E350 Sport
Thats incorrect information. 1) there is only a left rear fog light to assist cars in passing (on the left) during foggy weather, 2) the high beam and driving lights will not function at the same time to prevent blinding oncoming traffic. Correct, driving lights do not turn on using the "auto" setting...
And I don't have my manual with me, but I believe I recall reading that in the later-model cars the fog lamps do not come on with the low beams and are the only lamps lit in fog, for the foregoing reasons.
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From: austin, texas, usa
2006 e320 cdi
This goes back to my original question, what about driving at night in dense fog? I can see close (10 ft), but I can't see far with fog lamp alone.
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2008 E350 Sport
If it's that thick, you either shouldn't be driving, or should be driving at a speed that is consistent with the distance you can see. Most people rarely run into a circumstance where fog lights are the only option; they simply use their low beams. If the fogs only illuminate for ten feet, they aren't giving you any more visibility than you would get with the low beams, anyway.
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From: Tucson, Az
10 GLK350/ 15 Accord/ 94 Supra Turbo
Fog lights are for on coming traffic and should be yellow, that way they can see and avoid you. I would take your car to a MB dealer and find out if there is a program error, on dark nights I have my fogs and low beam on at the same time.
BTW, just to make sure we are not talking about the "fog/parking indicator" correct? the one that is all the way to the LEFT and is designed for you to be parked and is mainly used in Europe. If you turn the knob all the way to the right and pulled out you should have all your lights, low beam, fog lights, and fog/parking lights
BTW, just to make sure we are not talking about the "fog/parking indicator" correct? the one that is all the way to the LEFT and is designed for you to be parked and is mainly used in Europe. If you turn the knob all the way to the right and pulled out you should have all your lights, low beam, fog lights, and fog/parking lights
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From: austin, texas, usa
2006 e320 cdi
BTW, just to make sure we are not talking about the "fog/parking indicator" correct? the one that is all the way to the LEFT and is designed for you to be parked and is mainly used in Europe. If you turn the knob all the way to the right and pulled out you should have all your lights, low beam, fog lights, and fog/parking lights
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Another round of ICE
Fog lights are not for conspicuity. Daytime running lamps are. Fog lamps are for the sole purpose of helping you see under the fog for a short distance, which is commensurate with the low speeds you should be driving in those conditions.
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From: austin, texas, usa
2006 e320 cdi
As they should be. If you need fogs lamps due to dense fog, the lighting should be low to the ground to get under the cloud. Having normal headlamps illuminate at the same time would result in light bouncing off the impenetrable fog back into your eyes, constricting your pupils and deteriorating your ability to see.
Fog lights are not for conspicuity. Daytime running lamps are. Fog lamps are for the sole purpose of helping you see under the fog for a short distance, which is commensurate with the low speeds you should be driving in those conditions.
Fog lights are not for conspicuity. Daytime running lamps are. Fog lamps are for the sole purpose of helping you see under the fog for a short distance, which is commensurate with the low speeds you should be driving in those conditions.
Should low beam and fog light be mutually exclusive, or not? AzCamel says his low beam and fog light comes on at the same time.
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Another round of ICE
Now I am really confused. Should low beam and fog light be mutually exclusive, or not? AzCamel says his low beam and fog light comes on at the same time.
Should low beam and fog light be mutually exclusive, or not? AzCamel says his low beam and fog light comes on at the same time.
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In my 07 fogs and lows can be on at the same time. Lows are BIX btw.
And while we are at it.
A lot of older style BIX didn't illuminate right in front of the car like the newer ones do. Therefore older ones had fogs on in conjunction with lows; as did non-BIX, aka halogens
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From: Tucson, Az
10 GLK350/ 15 Accord/ 94 Supra Turbo
As they should be. If you need fogs lamps due to dense fog, the lighting should be low to the ground to get under the cloud. Having normal headlamps illuminate at the same time would result in light bouncing off the impenetrable fog back into your eyes, constricting your pupils and deteriorating your ability to see.
Fog lights are not for conspicuity. Daytime running lamps are. Fog lamps are for the sole purpose of helping you see under the fog for a short distance, which is commensurate with the low speeds you should be driving in those conditions.
Fog lights are not for conspicuity. Daytime running lamps are. Fog lamps are for the sole purpose of helping you see under the fog for a short distance, which is commensurate with the low speeds you should be driving in those conditions.
To the OP, make short vid. But if you are sure your low beams turn out it seems to be a relay broken or programming error.
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While I won't argue the usefulness of fogs or what you should do in different situations, but I've never experienced any car from any company shutting down the low-beams when fogs were activated. But all turn off the fogs when high beams are activated.
