DE independent Fog light mod
So I own a sport, didn't come with fog lights, I bought OEM fog lights, fog light bezel and the steering column stock with a fog light switch, plug-and-play, NICE. Everything was already wired in from factory.
I like my fog light control completely independent but could not find a DIY on the topic. I took a look at the wiring diagram and I see why.
I will be refering to the control side of the fog light relay. (Low load, no addition fuses required)
The ground side of the circuit was controlled by the BCM and the power side was controlled by the headlight relay. I tried to find another power source to bypass the headlight relay and found that the BCM will not provide ground without a headlight on input.
So simply put, we are going to bypass the BCM and provide a new power source.
The power source I'm using is also HOT AT ALL TIMES, so the fog lights will work even without the key in, just like the headlights.
If you want to make it work with KEY ON, I believe the Fan relay has a KEY ON power source on the control side of the relay.
Supplies and tools needed:
Female and male connectors (refer to the pictures to see what I mean by connectors)
Wire crimp tool
Pliers (to remove relay)
I RECOMMEND YOU TO DISCONNECT THE BATTERY BEFORE DOING ANY ELECTRICAL WORK.
REFER TO ALL THE PICTURES
---STEP 1: Power the Fog lights independently.
---locate the fuse/relay box near the battery in the engine compartment
---using the underside of the fuse box lid, locate the fog light relay
---Remove the fog light relay
---Make short wire extensions for the relay blades:
So I cut 3 short sections of wire, crimped a female connector on one side and a male connector on another on each one, YOU NEED 3 OF THESE
the fourth extension will be a bit longer, crimped with a female connector AT BOTH ENDS
(modification of male pins may be required due to different size blades of relay, I also attach a pic of that for example)
connect the wire extensions to the relay and connect them as shown in picture. They are simply extensions and plugs back into the same places they originally were in except for the female wire.
---STEP 2: Bypassing the BCM
The BCM will not output a ground signal to the relay if it does not have a headlight on input. Luckily the fog light switch itself provides a ground signal, we can use that to bypass the BCM.
---remove the glove box (squeeze the glove box at the top most inner parts)
---the BCM is sitting right there, see picture to locate blue and white connector
---See attach pictures to locate the wires on the corresponding connector you need to cut and connect together
---Cut BLUE/RED wire from BLUE CONNECTOR
---Cut BLUE/WHITE wire from WHITE CONNECTOR
---Connect the two cut wires together (harness side)
::::note:::: I have crimps on the connector side because I want to be able to revert the car to its original operation whenever I want to with ease. You can just leave them cut and taped up.
DONEEEEE, CHECK EM OUT!!!!!
I hope you guys could follow. I'm sorry if it's a bit confusing. If you have questions, I'll try to answer them to the best of my ability, I really suck at making these.
Last edited by kaph3n; 04-25-2020 at 09:47 PM.