How to get brighter DRLs with Fog Lights on

1

 

I build these (kind of) a lot. People will use them to drive grille lights or backlights (mainly on fog lights like the S3’s). That keeps what ever they hook them up to on with the DRL, parking, and low beams. The only thing I’d do different (besides the relay mentioned above) is use larger diodes. With grille lights and backlights, you can get away with 1A diodes easy. I’d use 3A for this since the DRL draws about 1.5A. Let me see if I have one here so you can kind of see it….

 

I only have the OEM LED version right now. But you can see the blue and green wires coming down and going to the diodes (1A) under the heat shrink in this case. But these would without the relay would make your DRL full brightness when the stalk is in any position but “off” if you ran that combined wire to the DRL input of the headlight. But hopefully it helps visualize what you’d want to do. Next time I build one for the halogen headlights, I’ll try to remember to grab a pic.

 

https://www.instituteofcaninebiology.org/schipperke.html DNA doesn’t lie

 

Like a slightly larger, shorter haired Pom Our black Pom looks a lot like a Schipperke. I think he is a German Spitz maybe? Its hard to tell. I have two that are litter mates. One is more spitz looking while the other is almost breed standard Pom.

 

Looking at the "coefficient of inbreeding", it looks like the Bouvier Des Ardennes (which I didn't even know was a breed until now) is like the Arkansas of the AKC

 

OP wants always bright. So in order to achieve that the DRL side requires juice always. If you add a relay (overkill), it would need to be on the TAIL circuit input. This would need to be before the diode so the relay cuts off the juice to the DRL side input. The relay then would have to be active after Low Beams are selected since the DRL input circuit goes to 0V. Parallel juice would not affect significantly the circuits.
Higher amp diodes are a good thing.


Puppy Killer

 

You are right if a constantly bright DRL is the goal. I thought the OP just wanted them full brightness when he turned on the fogs with the parking lights, not the low beams. Maybe I read into it wrong @TK2023 ? If the goal is just to have brightest DRL with the low beams as well, yeah, that’s easy enough. But I would recommend against that as DRLs are just going to be a source of glare at night.
Also, if you just want to use the fogs as a type of DRL, you could also wire them to come on with the DRLs so you don’t have to run the parking lights all the time. Once again, probably unnecessary and complicated, but doable.

 

What fogs do you have?

 

Yeah, like this. But throw an additional diode on the DRL wire.

We don’t talk about the blender incident…..

 

Once Low beams are selected the juice to the DRL circuit coming from the DRL relay is 0V. The DRL relay is ground controlled via BECU.

 

Yeah, on paper it shouldn’t need the additional diode, just like your original design wouldn’t. But I’d put it in there just because I don’t like any back feeding voltage. Some relays don’t like it.

 

If you want to avoid snarky comments, don't post your 'wanna do' thoughts here. Otherwise you're gonna get some constructive thoughts as well as the snarky ones. Deal with it.