Unlike most of the daytime running light questions I was able to find through searching, I actually want to add them, not turn them off. I just installed a set of aftermarket projectors with halos and LEDs, sort of like these: ebay link.

I want to use the LEDs and the halos as the DRLs. I'm thinking I can tie into the fuse for the wipers and washer fluid for power. The guy at O'Reilly's recommended this (sorry for the fuzzy picture):



The metal piece on the right slips over the fuse on the hot side, the fuse goes back in, and the female connector on the left then slips onto the metal piece now clipped onto the fuse. Then, you just crimp a wire onto the female connector on the left. All together, it looks something like this:



On the back of each headlight housing, there are two red wires (power for halo and power for LEDs) and two black wires (ground for halo and ground for LEDs). I'm thinking I can run the wire from the contraption in the picture above to the red wires on the headlights. Would I need to run more than one wire to the headlights, or can I run just one to one of the headlights, then another from the first headlight to the other? Then, I'm thinking I can just tie the black grounds into the ground for the headlight wires. Will this work? Is there a better way to go about this? Also, if I had to guess, I'd keep the fuse I'm tying into the same size, but let me know if that's right.

I'm also thinking of putting a switch in too so if I change my mind about running these as DRLs, I can just turn them off. Would that be just a matter of throwing a switch in the circuit, or is there more to it?

Obviously I have a little electrical knowledge - some would say enough to be dangerous - but if there's anything else I should think of, feel free to leave that too.

 

I'd think, with anything that's LED powered, you could just tie into any circuit that's hot with the ignition on. And, I don't see why you couldn't have an inline switch in the new circuit to the lights to turn them off if desired.

Edit: I just looked at the link, and if the halos are CCFLs, you MAY need a relay that uses the hot circuit as a "control". Then have it power the CCFLs through a dedicated line from the battery.


- Jack

 

As long as the halos do not draw too much power, using an add a fuse in any hot in run position ( wipers, radio, etc ) will work just fine.

I would suggest not using the one pictured above, as it can stretch out the fuse slot, and be too loose to install the fuse again.

Look for Add-A fuses instead.

 

The fuse slides through a slot in the extension I have pictured above. It doesn't change the size of the fuse. O'Reilly's had some extensions that wrapped around the fuse, but they recommended against using them for the same reason you mentioned. It could cause arcing if that extension were removed.

If the halos draw too much power, how will I know? Because the fuse blows? If that happens, I can't just add a bigger fuse, right? That's when I'll need to draw power directly from the battery like Jack mentioned?

Thanks for your help.

 

I kind of wondered about that too, Steve, but then I thought if ALL the devices on that circuit were on, there might be too much draw.

He could probably hot wire one to the battery with an ammeter in series to measure the draw, double it and then he'd know if the load was too great.

- Jack

 

Very true, this is to get a hot in run position circuit, of small load.
I think the add a fuse is good for a max of 10 AMP.

Without knowing the load of the DRLs to be added, the best route is what you suggested, using this to trigger a relay, with that fused ( per the load ) to the battery.

 

Thanks for the help, guys. I like the idea of a relay. I'll go pick one up this weekend and let you know how it works out.

 

Jack and Steve, I thought I'd provide an update, because I know both of you have been waiting on the edge of your seats to see how this turned out. Well, once I actually lit up the lights, I decided I didn't want to run them as running lights. The LEDs are yellow, and the "halos" are actually a round reflector with a couple of blue-ish LEDs in them. So I ended up deciding just to wire the yellow LEDs in with the parking lights and the halos with the low beam projector. Thanks again for the suggestions.

 

Good work! Glad you're happy with the outcome!

- Jack