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Discussion Starter #1
Hello folks,
I need some help. I want to run my fog as DRL. Fog is aftermarket OE style.
How can I wire up a relay to turn on with ign and off when low beam or parking light come on at night?
I don't understand how to wire a relay for it.

Long story short. I am running retrofitted headlights. So, I'd like to have DRL on the fog lamps instead.

Any help is appreciated.
 

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Discussion Starter #2 (Edited)
Will this work?
From relay.
30 - Ign fuse (underhood fusebox) using add a fuse.
87a - 12v+ of fog lamp
85 - 12v+ trigger source (parking, low or high beam 12v+ wire)
86 - Ground
 

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Yes it will work. I'd connect 85 to parking lights since they will be on with low or high beams.
Or if your new fogs are LEDs you can do it all w/o a relay by powering them directly from IGN power and connecting their ground to the parking lights.

But in either case the high beams which are connected in series with each other by DRL relay 3 will still work as DRLs. You can defeat them by replacing the relay with a 4-pin relay. Then use the 5-pin you just removed for your new circuit.
 

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Discussion Starter #5 (Edited)
Well, it didnt work.
The 30a AM2 fuse is Hot ALL the time. Even without the key in the ignition.

End up tapping into the EFI No. 2 for power. EFI No. 1 will also work. Those 2 only get hot if the key is ON.
147282
 

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I have wired a fog light before and the 87a makes the fog light stay on with the ignition key off. But when you wire it to 87 it will come on with the ignition only.
 

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Discussion Starter #9
Gotcha. I'm going to do some more test and see when I have a little more spare time. But for the time being, it works with 87a used on my set up.
 

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I have wired a fog light before and the 87a makes the fog light stay on with the ignition key off. But when you wire it to 87 it will come on with the ignition only.
In this case 87a is the correct pin since the desired result is the opposite of a normal fog light connection. He's getting ignition switched power on pin 30, which with the relay de-energized sends power to his fogs being used as DRLs via 87a, the normally closed pin.
Then when the relay is energized by the head or parking lights the DRLs go off.
 

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Discussion Starter #11
Something strange is happening with my setup.
The fog would randomly turn ON in the middle of the night. ON for a second then OFF.
Is the Injector Fuse randomly getting power? Like a self check or something?
 

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One never knows what's happening in the ECUs these days. I've measured quiescent (car off) battery drain current on a few newer cars and found it steps down gradually over several minutes as apparently different systems are shutting down. Maybe some of them re-energize periodically.
So try EFI #1 or another key-on circuit.
 

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Discussion Starter #13
That's what I'm thinking, about another fuse spot to tap. It seems strange that's all. Only reason I notice was because my motion security camera inside the garage tripped. Happened 3x last night. 3a, 5a, and 8am this morning.
If the EFI 1 spot doesn't work, I may have to extend the wire longer over to the other fuse box.
 

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Discussion Starter #14
End up pulling power from the #6 ECU-IG1 10a fuse under dash, driver side. No more random power ON in the middle of the night.
147617
 

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Thanks for the info. I just installed halo projector headlights on out '06 and was going to power them off the underhood EFI fuse you mentioned. But since I didn't want to take a chance on the random effects you noted, I ran a wire thru the firewall and connected to the blue wire right above the IGN relay behind the dash panel. It probably goes to the same fuse power bar as the #6 you used but easier to get to. Has power on Start and Run. Since the halos only take .5A I ran them w/o a relay. Will be eliminating the high beam DRLs by installing LEDs.
Another neat thing I did was make the halos blink the opposite of the signal lights. Kinda looks like they're winking! Did it by grounding them to the hot lead of the stock halogen signal bulbs.
 

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Take a look at the enclosed PDF, this is how I envisioned wiring up the fog lights for DRL, yet still maintaining its OEM function.
  • Page 1 shows the wiring using two relays: one SPST, one SPDT. You might be able to eliminate the SPST and wire ignition straight into the 87A terminal of the SPDT, but having the SPST is an added safety making sure the fogs don't burden the ignition load.
  • Page 2 shows when the vehicle is on, SPST switches on, sending power to SPDT 87A terminal, which is normally closed with SPDT 30 terminal, thus, turning the fogs on.
  • Page 3 shows when either the low beam or parking light is on, SPDT switches on and disconnects 30 from 87A, and connects to 87. However, since there's no power on 87, fogs stay off.
  • Page 4 shows the OEM switch turning on the fogs and the fog dash light should turn on. If you turn on the high beam, the fogs should turn off as intended.
You should be able to use just these two relays to control and power on/off both fogs. LMK if it makes sense. I may be off with my other ongoing project. ;)
 

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Discussion Starter #18
Yeah, that make sense. When I bought the vehicle, being a base model, I tried to install the fog using one of the guide on this site. But I couldn't see any pre-ran wire from factory for the fog. So I end up using the wiring from the cheap fog kit I purchased on eBay. It did came with relay. Now it's working as I want it to, but no dash icon like your setup. Your is much more factory like.
 

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Gotcha. Base model never came with fogs, but like yourself, I was under the impression that factory wiring was there. The dash icon would only work if both (1) factory column switch with fog light on/off and (2) FR Fog Relay were installed. I thought yours may have been a Sport or Limited model, then the fogs and other parts would've been included. Regardless, it's working as you intended.
 

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I would never connect anything else on ECM power fuses. If your fog light gets shorted for some reason or another, you lose ECM power. That's very dangerous.
 
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