DRL LEDs - Wiring them correctly

[BMAN_986]

I want to wire in some LED DRLs to sit inside the front grills. I want to do this right so that they are always on when the car is running except when the hi/low beam is on (then they should be off). I believe this is the legal way to have DRLs wired. It is also the most considerate way to oncoming drivers :-)

It appears I can use the attached 12v relay diagram to do this.

Here comes the hack ...

It seems the easiest place to do this wiring is behind the light switch because everything I need is there. I then just need to run my DRL wires up to the relay.

Alternatively I will have to cut the feed to both headlights somewhere post the switch (and other relays?) and wire them to this relay. I'm also going to have to create a loom off the battery and tap into a live +ve feed somewhere. I hope I explained that right :-)

I don't want to do the fog light hack. In Seattle we need them a fair bit as well as DRLs!

Any thoughts?

[Burg Boxster]

Seems you're over complicating this a bit... DRLs (Daytime Running Lights) can be on regardless when hi and/or low beams are on (or not)...

To that end, all you need is a +12V switched feed for them... and assuming [very low draw] LEDs, you could potentially eliminate the relay [and aux battery feed too, etc.].

Good luck

[particlewave]

I'm with BMAN. I plan on using the halos on my projectors as DRLs and do not want them on all the time. Off when headlights are on...DRLs that are on all the time look very tacked on.

Also, since the halos are inside of the headlight housing, they would be a huge pain to change, so having them always on would be unwise.

JMO

[BMAN_986]

@Burg. Yes I could wire them that way but from my understanding unless "always on" is OEM fitted, it is not legal.

At night DRL LEDs give off an incredible amount of flair because the beams are not focused which is bad for oncoming drivers. I believe in OEM setups where the DRLs remain on, they dim the DRLs when the main beams are on. Effectively the DRLs become cosmetic. It's a similar problem when people put aftermarket HID bulbs into regular lights.

Also, I've been looking at other newer Porsches and they all have behavior I was describing so hopefully it gives me a more OEM feel :-)

@particlewave. Do you have the "ebay" projector lights with the built in DRLs? I have those too disconnected the eyebrow part. The lights don't look so corny when they are on now and the LED turn signals is enough to give the car a fresh look.

[particlewave]

No, I went with standard de-ambered headlights, which I then installed hid projectors into.



The halo that I want to use as DRLs



The halos are powered by the wiring that was for the small running/parking light inside the OEM headlight. I assumed that they shut off when the headlights were turned on, but they do not.

[BMAN_986]

So I decided to do this job last night. All in all it took a little over 4 hours. Here's a summary and some photos of the install ...

The DRL kit. Ordered from Ebay



I need to ensure I can power them with 10w-15w fuse



Given the way I want to set this up (my original post) I needed a fused feed which is live when the ignition comes on and a feed when the main beams come on. So I decided to go straight to the fuse box. There are a few screws but this thing is pretty easy to take off and out.



After a few volt meter tests I found that the fog lights are live (without being on) with the ignition and the main beam remains live once they are switch on (regardless of high beam or fogs). From the relay diagram



Pin 30 goes to the fused side of the fogs -> Row A Fuse 7
Pin 86 goes to the fused side of the main beam -> Row A Fuse 10



Because the fogs and DRLs can never be on at the same time, the 25w circuit is more than enough.

I created a two wire loom



And a nice label to attach to the loom behind the fuse box



I spliced right into the wires and soldered and taped


The fog is a purple wire
The main beam is a brown on yellow.

I cable tied the loom back up the original car loom. This is important to keep cable tight. I cable tied all the way underneath the drivers dashboard. Loose cables mean rattles!


... this also allows you to run the the cable through the bulkhead just above the the steering column. There's a large gromet you can go through. It comes out behind the battery on the left side. Move the battery to make it easier to push through and route the loom to the right hand side of the car. I don't have any pics of this but can take some if you like.

This pretty much finishes inside the car. Do not reassemble until everything is done

Next I position the DRLs inside the grills.

[BMAN_986]

I'm putting them in the middle so I cut the vertical supports. The integrity of the grill doesn't weaken that much.



Remove the headlights. You can get to the top of the grills from there. This is how you will reach the DRL wires.



If needed, cut the excess trim of the DRL using a dremmel.


Put the DRLs in the grill. Do not secure right now. Route the DRL cables so that when you put the headlights in you won't catch the cable. Feed the DRL cable into the trunk space through this opening



Next wire up the relay

Add a grounding cable to this post



Once you have this, you'll have all the wires in the same place. Create a mini loom and cut all the cables to the same length. Then solder the relay to the DRL/Ground/Feed loom wires



Pin 30 is from the custom feed loom (Fog +ve)
Pin 86 is from the custom feed loom (Mainbeam +ve)
Pin 85 is the DRL Ground (DRL Blue Wire) and Ground Post.
Pin 87a is the DRL +ve (DRL Brown Wiire)

Tape it all up and place the relay in the cavity like this. You can cable tie it to keep it secure.



You should now be able to test


Once you are happy that everything is working go ahead a run this test.

Car ignition on -> DRL On
Side Lights -> DRL On
Main Beam -> DRL Off
High Beam -> DRL Off
Fog -> DRL Off/High Beam Off

If everything looks good you are done. Secure the DRLs. Put all the trim back (inside and outside the car)

Finished picture.



I'll try and get a video up to demo the behavior.

btw, particalwave ... nice color ;-)

[evo-r]

Awesome job, they looked great!!

[particlewave]

Nice work BMAN!

I like that idea...I think I'll do something electrically similar. I'm thinking of building a small circuit which the led power runs through. Switching would be done by a transistor and controlled by a jumper from the low beam...this way I can keep it all inside of the headlight housing.

Awesome color, hehe!

[BRAN]

...that topic never gets old

I have a pair of Hella LEDayFlex II and their IKEA style wiring diagramm...
Ignition on = DRL on
headlights on = DRL off


TASK: I don't want to run any cables inside to the switch, relay or fuses = All cables should be attached in the frunk area.

QUESTION: headlight low beam cable = Can I find it in that harness (s. pic)


switched plus = black/yellow (from the spray jet washer was used, I've read)
and the rest is no problem.

THANK YOU,