2004 to 2020 Mazda 3 Forum and Mazdaspeed 3 Forums banner

1 - 1 of 1 Posts

10 Posts
Discussion Starter #1
Now before I go into how to do it, I want to first point out that I already know about the alternative method of connecting the wires inside the dash panel. However, that method only works when you have the parking lights active. This method keeps them as daytime running lights without the need to turn on the parking lights, and still utilizes the factory fog light switch when the headlights are turned on. So if there is already a write up on how to do it this way as well, then I apologize in advance for wasting a thread, but here goes:
To start, you're going to need 2 relays. I'm not sure of the technical terms for which kind it is, but it's the one that has the numbers 85, 86, 87, 87a, and 30. You're also gonna have to get to the Fog Light wires behind the fog light assembly. The wire you'll need is a green wire on both sides. Once you find it, you're gonna have to cut the wire. After you cut it, you'll have a Fog Light + Bulb side, and Fog Light + Engine Side. Once you have that, wire the relays like so:

85: Ground Out
86: Low Beam (+)
87a: Ignition (+)
87: Fog Light (+) Engine Side
30: Fog Light (+) Bulb Side
Do this for each fog light.

When wired this way, your fog lights will now run as true daytime running lights, but when you turn your headlights on, the relay switches the power to the cars factory wiring. This means the fog lights still turn off with the factory switch, and they also turn off when you turn the high beams on, making this method 50 states legal. The only downfall I can see with this, if you see it as a downfall is that with this wiring method, the fogs can't turn off unless the headlights are on. If this is a deal breaker, then instead of running 87a to Ignition (+), run it to the fog light switch (+) trigger and that should be all there is to it. Well, thanks for reading, and sorry again if this is old news.
On a side note, the picture I included of the fuse panel shows which ignition (+) I tapped into. This particular trigger remains on for 25 seconds after the car is shut off, so it's like how some cars' headlights turn off a little bit after the driver leaves. What's cool about this find, though, is that it now seems possible to do a quick 'n easy DIY turbo timer.


1 - 1 of 1 Posts