HOW-TO independent fogs

[pcvang]

So this is my first How-to, so hopefully it turns out good. I've seen a couple of a couple of How-to's for this, but didnt like the fact that you had to run all that wire. I figured all that wire is already there and its basically just a switch signaling a relay to switch on the fogs. I studied the wiring diagram and found what controls the fogs to only come on when the headlights are on. The switched ground coming from the fog light switch is intercepted by the BCM (body control module), which then signals a ground to the fog light relay to energize the relay. Well the BCM needs to see the headlights on in order for it to signal a ground to the relay. So what I did was bypass the BCM so that the fog light switch will directly signal the fog light relay.

Parts list:

6" of wire 16 or 14 gauge
2 butt connectors (optional, some people dont mind twisting wires together)
electrical tape

Tools:

flat head screwdriver or a plastic interior pry tool
wire cutter
crimper (optional, again, some people dont mind twisting wires together)
test light (optional, but I recommend it so you can check your circuits/wires)


From this picture you can see what I'm talking about. The X's are where the wires need to be snipped and the line is where it needs to be connected.

[IMG][/IMG]

The BCM is located right behind the fuse panel inside the left side of dash. You will need to remove the lower part of the dash. My hands were small enough where I just had to pull the dash back.
Note: be careful when sticking your hand in here, I cut my hand on that metal bracket there

[IMG][/IMG]

[IMG][/IMG]

This is the first wire that needs to be snipped. DO NOT snip yet! There are 4 plugs on the BCM. This wire is located on the lowest plug.
Note: before snipping this wire I would recommend that you test this wire. You do so with a test light. You are testing for ground so put one end on positive and test for ground. What I did was stuck a paper clip into the cavity of the harness so it touched the terminal and then touched my light to it. Once you done that, switch on the fog light switch and it should light up.

[IMG][/IMG]

This is the second wire that needs to be snipped. DO NOT snip yet! There are 4 plugs on the BCM. This wire is located on the upper most plug.
Note: before snipping this wire I would recommend that you test this wire. You do so with a test light. You are testing for ground so put one end on positive and test for ground. What I did was stuck a paper clip into the cavity of the harness so it touched the terminal and then touched my light to it. Once you done that, turn on your headlights and then switch on your fogs and it should light up. You will notice this will only light up with the headlights on (this is the reason why you need the headlights on to turn on your fog lights).

[IMG][/IMG]

Now that you know which wires you need to snip, you will want to disconnect your battery before proceeding (these wires are only ground switched, but its better safe then sorry). Go ahead and snip both these wires. The two wires that are coming out of the BCM will need to be taped off so they dont touch anything.

Next, take the other two ends and connect them together, with your butt connectors or how ever you want to connect them.

[IMG][/IMG]

Now go ahead and reconnect your battery and test them out. They will now turn on with the parking lights on. In the diagram above, it shows the power source for the relay being hot at all times. I find this to be incorrect. It is actually hot with the parking lights (this is why now the fogs come on when the parking lights are on). I liked it like this so you wont accidently leave your fogs on. Some people may prefer to have it totally independent. I suppose you can make that power source hot at all times but I'll leave that up to you to do.

[IMG][/IMG]

Check your wires make sure everything is good, not touching, taped off, and your connections are tight. You can put your dash piece back on now because your done!

Hope this helps.

I dont know if there is suppose to be any disclaimers or anything, but if there is, then mods please add.

[helmetface]

Well written, I just don't understand it's purpose.



Extremely Hard Parking?

[pcvang]

Originally Posted by helmetfail Well written, I just don't understand it's purpose. Extremely Hard Parking?

yup!

[MazdaPoPo]

Originally Posted by pcvang So this is my first How-to, so hopefully it turns out good. I've seen a couple of a couple of How-to's for this, but didnt like the fact that you had to run all that wire. I figured all that wire is already there and its basically just a switch signaling a relay to switch on the fogs. I studied the wiring diagram and found what controls the fogs to only come on when the headlights are on. The switched ground coming from the fog light switch is intercepted by the BCM (body control module), which then signals a ground to the fog light relay to energize the relay. Well the BCM needs to see the headlights on in order for it to signal a ground to the relay. So what I did was bypass the BCM so that the fog light switch will directly signal the fog light relay. Parts list: 6" of wire 16 or 14 gauge 2 butt connectors (optional, some people dont mind twisting wires together) electrical tape Tools: flat head screwdriver or a plastic interior pry tool wire cutter crimper (optional, again, some people dont mind twisting wires together) test light (optional, but I recommend it so you can check your circuits/wires) From this picture you can see what I'm talking about. The X's are where the wires need to be snipped and the line is where it needs to be connected. [IMG][/IMG] The BCM is located right behind the fuse panel inside the left side of dash. You will need to remove the lower part of the dash. My hands were small enough where I just had to pull the dash back. Note: be careful when sticking your hand in here, I cut my hand on that metal bracket there [IMG][/IMG] [IMG][/IMG] This is the first wire that needs to be snipped. DO NOT snip yet! Note: before snipping this wire I would recommend that you test this wire. You do so with a test light. You are testing for ground so put one end on positive and test for ground. What I did was stuck a paper clip into the cavity of the harness so it touched the terminal and then touched my light to it. Once you done that, switch on the fog light switch and it should light up. [IMG][/IMG] This is the second wire that needs to be snipped. DO NOT snip yet! Note: before snipping this wire I would recommend that you test this wire. You do so with a test light. You are testing for ground so put one end on positive and test for ground. What I did was stuck a paper clip into the cavity of the harness so it touched the terminal and then touched my light to it. Once you done that, turn on your headlights and then switch on your fogs and it should light up. You will notice this will only light up with the headlights on (this is the reason why you need the headlights on to turn on your fog lights). [IMG][/IMG] Now that you know which wires you need to snip, you will want to disconnect your battery before proceeding (these wires are only ground switched, but its better safe then sorry). Go ahead and snip both these wires. The two wires that are coming out of the BCM will need to be taped off so they dont touch anything. Next, take the other two ends and connect them together, with your butt connectors or how ever you want to connect them. [IMG][/IMG] Now go ahead and reconnect your battery and test them out. They will now turn on with the parking lights on. In the diagram above, it shows the power source for the relay being hot at all times. I find this to be incorrect. It is actually hot with the parking lights (this is why now the fogs come on when the parking lights are on). I liked it like this so you wont accidently leave your fogs on. Some people may prefer to have it totally independent. I suppose you can make that power source hot at all times but I'll leave that up to you to do. [IMG][/IMG] Check your wires make sure everything is good, not touching, taped off, and your connections are tight. You can put your dash piece back on now because your done! Hope this helps. I dont know if there is suppose to be any disclaimers or anything, but if there is, then mods please add.

wish ur diagrams were slighty better. bery vague, and u cant tell where alot of these wires are. theres tons or orange and green wires in there

[helmetface]

Originally Posted by MazdaPoPo wish ur diagrams were slighty better. bery vague, and u cant tell where alot of these wires are. theres tons or orange and green wires in there

Honestly, open up the panels, you'll understand it a lot better..I'm not even on the same platform and I found it easily read.

Secondly, I FUCKING HATE when people quote several pictures...especially when it's just 2 posts up..

[2008speed3]

Originally Posted by helmetfail Secondly, I FUCKING HATE when people quote several pictures...especially when it's just 2 posts up..

its a jersey thing

[fishin53]

i like this way better than having to wire each fog light separately with a separate relay.

[pcvang]

Originally Posted by fishin53 i like this way better than having to wire each fog light separately with a separate relay.

Yes. this is a very straight forward method.

[SLOWHATCH]

I wonder if there are any differences in the wiring from 2010 w/ tech to 2011 w/ tech. I'll look into this soon.

[bms3mtb]

Originally Posted by pcvang Yes. this is a very straight forward method.

OMG YES!

Thank you, Thank you, Thank you!!! I spent an hour staring at this fucking diagram and splicing wires at the stalk (headlight switch) and kept coming up empty. A Million billion thanks because relays are fucking stupid and this is WAY smarter!

Ugh if I could figure out how to donate MSF bucks I would. Seriously no homo I love you.

[pcvang]

Originally Posted by bms3mtb OMG YES! Thank you, Thank you, Thank you!!! I spent an hour staring at this fucking diagram and splicing wires at the stalk (headlight switch) and kept coming up empty. A Million billion thanks because relays are fucking stupid and this is WAY smarter! Ugh if I could figure out how to donate MSF bucks I would. Seriously no homo I love you.

LOL. i stared at it a long time too.

Originally Posted by SLOWHATCH I wonder if there are any differences in the wiring from 2010 w/ tech to 2011 w/ tech. I'll look into this soon.

Actually the diagram i used is for a 2010 ms3. Since mitchell on demand didnt have wiring diagrams for 2011 yet when i did this. There was no variations between the tech and non tech either. If you wanna make sure, just test the wires.

[Sid3wayS]

@pcvang
Maybe Im just real dumb but could you possibly explain a bit better how you pulled that entire piece forward? Are there any screws or is it all clips?

[SLOWHATCH]

Originally Posted by Sid3wayS @pcvang Maybe Im just real dumb but could you possibly explain a bit better how you pulled that entire piece forward? Are there any screws or is it all clips?

It's all held in by clips. When I did other stuff in that area I pulled the left footwell piece, open the fuse box and pull down on that whole side. It will just pop loose.

[StayBroke]

Why not run a 12 volt line to the factory fog switch then run the other wire to the actual fog light wire in the harness. This way you can use the factory switch and not have parking lights on when fogs are on. Just a suggestion.

[pcvang]

Originally Posted by StayBroke Why not run a 12 volt line to the factory fog switch then run the other wire to the actual fog light wire in the harness. This way you can use the factory switch and not have parking lights on when fogs are on. Just a suggestion.

You will end up burning up your switch or wires. Im not sure what the operating amperage is for the foglights. But i figure anywhere from 10-20 amps.. that is too much amperage to to be running through 18ga wire (not sure exactly what gauge it is) and switch. switch is not made to run that high of amperage. cars nowadays run a switched ground so theres less chance of hot/positive wires being short circuited and burning up.

[StayBroke]

Heres the specs on hid ballast

Power consumption: 35watts
Voltage: 85V +/- 17V
Luminous flux: 2800
Service Life: up to 3000hrs
Input Voltage: 9V-16V
Working current (Steady state): 3.5 A nom
Ignition voltage: 24kV Peak Max, 18kV Peak Min
Lamp Frequency: 450 Hz

wonder if it will hand 7 amp but i dont have my car as i would look and see what the actual switch could handle.

[bms3mtb]

Originally Posted by pcvang You will end up burning up your switch or wires. Im not sure what the operating amperage is for the foglights. But i figure anywhere from 10-20 amps.. that is too much amperage to to be running through 18ga wire (not sure exactly what gauge it is) and switch. switch is not made to run that high of amperage. cars nowadays run a switched ground so theres less chance of hot/positive wires being short circuited and burning up.

Biggest reason? Car doesn't beep at you when you leave the fog switch on, wait for that mistake to happen when you don't notice they're on cuz it's daylight

Going to do this NOW!

And done..



Now I can get HIDs... was waiting to be able to pull into the driveway and see without blinding the house.

[mr.panec]

I am confused, as I tore apart the dash and tested the two wires for this project. With parking lights on, wires are live (test light turns on). With headlights on, wires are dead (test light turns off). The exact opposite of what your test results are.

What am I missing, or am I not understanding the test? I appreciate your feedback.

[pcvang]

Originally Posted by mr.panec I am confused, as I tore apart the dash and tested the two wires for this project. With parking lights on, wires are live (test light turns on). With headlights on, wires are dead (test light turns off). The exact opposite of what your test results are. What am I missing, or am I not understanding the test? I appreciate your feedback.

what are you testing for? you should be testing for ground. which means you need to put the other end (alligator clip-assuming your using a typical test light with clip on one end and light and probe on the other) to battery positive (you may need to run and extension wire from battery to your test light). with the orange wire, with lights on or off, it will ground once u flip the fog switch. for the green wire, with headlights ON, it will ground once u flip the fog switch and only with the headlights ON. remember your testing for ground, this is a switched ground circuit.

[rghispanic88]

Originally Posted by Sid3wayS @pcvang Maybe Im just real dumb but could you possibly explain a bit better how you pulled that entire piece forward? Are there any screws or is it all clips?

you wanna try this next time we meet?

[Sid3wayS]

Originally Posted by rghispanic88 you wanna try this next time we meet?

Hell yeah.

[fishin53]

just did this the other day and just went and cut the wires w/o testing. just look and double check they are the right ones

oh and fyi the fogs stay on if you put your high beams on (non tech package head lights).

other than that i like this little bs rice mod, now i just need some new bulbs.

[Hatchbackfan]

Doing this tomorrow!

[chintastic]

Make a how to video

[ms3will]

Thank you so much for figuring the Indy mod out dude! This made my day!!!!:-)

[triphop631]

You have to have small hands to do this otherwise it is a breeze

Sent from my DROID RAZR using Tapatalk 2

[Dubcnea]

Originally Posted by helmetfail Secondly, I FUCKING HATE when people quote several pictures...especially when it's just 2 posts up..

as i was scrolling...i was thinking this EXACT thing. so this x 2. awesome write up by the way. i've often wanted this but don't have the technical know-how to figure out the relay stuff. i'm glad someone else does.

[Dubcnea]

i actually went out to try this but could not get the bottom of the dash off. there is a screw behind the hood pop that i could not get to. that is apparently holding the plastic piece on from the bottom. i could flex the plastic some but not enough to have room to get my hands in there to do anything. also it appears that i have a few more wires in there than the OP. i found the wires i needed to snip but it was harder to weed them out. argh. mod on hold i guess.

[ruthless013]

Originally Posted by SLOWHATCH It's all held in by clips. When I did other stuff in that area I pulled the left footwell piece, open the fuse box and pull down on that whole side. It will just pop loose.

this right here is the key. no need to remove the screw behind the hoodlatch - just pull out footwell piece, pull out fuse box door, then grab the panel and pull towards you and down. it won't pull completely off, but will break away giving you more than enough room to do the work.

took me all of 20 minutes, this how-to couldnt lay it out any clearer.

had this same setup on my old civic with the 'jdm-yo!' square foglights.

thanks OP for being smart.

[Dubcnea]

maybe i'll try it again sometime soon. i was nervous i was going to break the damn plastic. it was flexing a lot but wouldn't come down. i couldn't get my hands in there with just the bit that had come down already. damnit.

[PoisenSpeed3]

Did this today the instructions couldn't be written any better. Took me 45 mins as i soldered everything. Worked first time and i didn't use a test light. Just doubled and triple checked everything before i cut. GREAT WRITE UP!!!

[Shad]

Going to do this mod this weekend. Thanks for the easy write up!!!

Done!!!! As has been said before, great write up! My first mod to my 2012, it was easy, cheap and looks super cool...

[apawk]

Originally Posted by babypetit how many screws are on the lower dash piece? can't seem to get it out properly and have big hands that can't into the small space when it is lowered a bit to do this mod

Will this same wiring scheme work on 08 MS3? Thanks in advance for the info

[Sigmabond]

Originally Posted by fishin53 just did this the other day and just went and cut the wires w/o testing. just look and double check they are the right ones oh and fyi the fogs stay on if you put your high beams on (non tech package head lights). other than that i like this little bs rice mod, now i just need some new bulbs.

Just a FYI for those cars in states that require an inspection. If the fogs are on while the high beams are on then, in VA at least, its an automatic fail of state inspection.

Virginia the high beams count as 4 lights according to the code. So even fogs with the high beams counts as 6 lights. Thats one of the reasons you can't turn on the factory fog lights with the high beams on. (credit to rgjones thenewx.org)

Doesn't make much sense but that's the law here at least.

[fishin53]

im in jersey and they only give a fuck if you have a check engine light i think.

idk the exact way they do it now cause im good till 9/2014

[SofaKingAwesome]

so maybe I'm special, but do you just tape/cap off the other end of the wires you snipped?

[minger]

I just tried this...and now the fogs don't work at all. Wired it up correctly (didn't test beforehand...mistake right there) and got nothing, and then returned it to stock and still nothing. Fuse for fogs is fine - any ideas?

Second thought - I think I wired the two ends that came out of the BCM instead of the two other wires. Any ideas what I may have done by doing that?

[fishin53]

you wire the other 2 wires together you directly bypass the bcm

and for those that are concerned about passing inspection im thinking you can just unplug the fog lights when you go, cause you dont need them. most cars dont even have fog lights. just a thought dont hold me to it

[pcvang]

Originally Posted by SofaKingAwesome so maybe I'm special, but do you just tape/cap off the other end of the wires you snipped?

Yes taped off

Originally Posted by apawk Will this same wiring scheme work on 08 MS3? Thanks in advance for the info

No.

Originally Posted by minger I just tried this...and now the fogs don't work at all. Wired it up correctly (didn't test beforehand...mistake right there) and got nothing, and then returned it to stock and still nothing. Fuse for fogs is fine - any ideas? Second thought - I think I wired the two ends that came out of the BCM instead of the two other wires. Any ideas what I may have done by doing that?

Should be ok. You figure it out?

[minger]

Thing is - I didn't test it with the two wires that aren't coming from the BCM, but it's weird that it isn't working even when switched back to stock. I'll try that later today, but I'm slowly freaking out...

Think I may have done something to the relay? I'm trying to figure out if the two parts coming from the BCM are hot or not...if wired together and both hot, it shouldn't be that big of a deal?

Looking at this again, if I just bypass the BCM this should all work...but then stock doesn't work still. I'll be trying this later today. Something that shouldn't have any signal (grounded?) to itself should still be gounded...I think