Keeping fog lights on without low beams?

Rommy

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So I was at a civic X meet the other day and I noticed someone had their fog lights on with only their DRLs on, no low beams. I forgot to ask the person how they did that. Is there a way to keep only the fog lights on without wiring a manual operation switch to the lights to operate them independently?





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Shankmeyster

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Someone made a whole thread trying to figure out how to do this. He couldn't figure it out but was still working on trying to. Search for the thread as it should be in here.
 
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Rommy

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Spent an hour searching, can't find it for the life of me. Anyone know any additional info?
 

CivicXander

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Unplug the headlights or make a switch in the circuit
 

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Edit: Removed original idea as it wont work.


You have options but non that will rely on the fog switch in cabin. You can wire them to your DRL but will require a relay somewhere.

Two easier options:

1) You can modify the relay for the fogs in the fuse box to be turned on from the DRL signal using a fuse tap on the DRL fuse (assuming its switched).

2) Buy an H8 relay harness and power the fogs with an inline fuse from battery and signal the relay on the harness with the DRL connector behind the headlight.

Both solutions are faily ugly.
 
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Cars stopped being able to do this right around the early 2000 era. E39 Bimmers can do it, E34 and so on... but on a German car its easier to figure out how to make them function that way since European market cars are able to do so.
 

SSGCoxie

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The problem is that the fog light relay under the hood is controlled by the BCM (body control module). This BCM is programmed to not allow fogs without low beams. A separate switch could be used to power the fogs independently, but you would lose the dash indicator when they are on as the BCM also controls this. It's possible, but not very pretty.
 

Dr_Drache

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The problem is that the fog light relay under the hood is controlled by the BCM (body control module). This BCM is programmed to not allow fogs without low beams. A separate switch could be used to power the fogs independently, but you would lose the dash indicator when they are on as the BCM also controls this. It's possible, but not very pretty.
so what you are saying is - we need to mod the BCM - easy peasy!
 

Romeoridgee

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jump the fog relay negative wire (on my 19 sport its on bcm connector b wire 15 purple) and the fog light activation wire (on my 19 sport its on bcm connector c wire 6 purple). fog switch wire will complete the ground for the fog relay and keep fogs on as long as switch is on, like the low beam lights, even if car is off. and will stay on when high beams are switched on.
 

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jump the fog relay negative wire (on my 19 sport its on bcm connector b wire 15 purple) and the fog light activation wire (on my 19 sport its on bcm connector c wire 6 purple). fog switch wire will complete the ground for the fog relay and keep fogs on as long as switch is on, like the low beam lights, even if car is off. and will stay on when high beams are switched on.
Will this allow for the dash indicator for fog lights to still function even when low beams are off?
 

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Will this allow for the dash indicator for fog lights to still function even when low beams are off?
No I noticed because the computer doesn’t know the fog lights are grounded. The command is not aloud without low beams on. You’re basically bypassing the computer.
 

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I haven't installed this yet, but I've made the harness up already. The NC contact on the relay allows OEM fog operation, energizing the relay with a switch allows override from OEM function. This way, you can have fogs automatically switch off when Highs are on, or leave fogs on all the time, incl when headlights are off and only DRL's are illuminated.
https://www.civicx.com/forum/threads/fog-light-override-capability.60376/

It's imperative that you actually switch the positive on the fog and not the ground. - otherwise when the relay is operated, you'll be placing a fault-to-ground and blowing the fuse (which I haven't drawn) or worse. On my 2016, the positive fog light wire is blue.
 
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