DIY 2012 Civic Si Independent Fogs (picture heavy)

boejoula

boejoula

Well-Known Member
215
68
Vehicle Model
Civic Si
Body Style
Sedan
This si my first DIY so i apologize ahead of time!

You will need to purchase:
An external switch
A relay
Blue male spade
Yellow T-Tap
15AMP Fuse

First thing you want to do it locate the factory fog light relay. It is under the hood, on the right side of the engine bay.



On the right side of the fuse box you will see the relays. You want the 5th fuse from the top, pull it out (to double check this is the correct fuse turn the fogs on and make sure they dont come on). Your going to use a male spade connector without the plastic to plug into where the power was fed by the factory relay. I used a 16 gauge wire.



Drill a hole just big enough for the wire to fit on the side of the fuse box and feed the wire through. Your going to run this along the loomed wires on the outside of the fuse box towards the headlight.




You want to go under the rad support and into the fender. Here's where you want to take the fender liner out/down on the right side of the wheel well. Refer to http://9thcivic.com/forum/threads/resonator-delete-si-sedan.4811/ for pics of the wheel well liner (THANKS@smokedditty) YOU WILL BE REMOVING THE 3 PIECES HE HAS MARKED WITH AN X

Once you get the liner out of the way, lightly wire tie the new fog light wire to the hood latch so it doesn't dangle. Right under the gromet for the hood latch is an empty gromet the you will drill a small hole through to get your wire into the car



This is the other side of the gromet, again, right below thr hood latch cable.



Now your going to want to get the switch and relay.

First, remove the under dash panel
http://www.collegehillshonda.com/instructions/civic/2012/4dr/ambientlightsi.pdf page 3

T-tap the main ignotion wire. It is the orange wire at the top of the interior fuse box


Wire up the switch depending on what type of switch you have. My switch looks like this:


And the wiring (leave a little slack on the wire for reinstalling the panel):


This is the wiring diagram for the relay



Once its all wired up, connect your new fuse and test these bad boys



Not sure how to do this on models without factory fogs but i would imagine it to be the same.
Any more questions, ask them here or send me a PM. happy to finally give something back to the community!

webby i hope this is up to par for the DIY. Enter me into the next contest please!!
 
boejoula

boejoula

Well-Known Member
215
68
Vehicle Model
Civic Si
Body Style
Sedan
You may be able to but i don't remember If it all worked internally. You cut the wire from the stalk and use that to trigger the relay. You would have to wire the relay differently. I can make a diagram for that if you would like. Still would have to run the wire out to the fuse box. But after all that, it may still only work with the headlights
 
Brooksie365

Brooksie365

Well-Known Member
820
570
Worcester, Ma
Vehicle Model
Civic Si
Body Style
Sedan
is there a diagram of the original relay? just curious i know it was mentioned but you should be able to jump the positive of the relay to the signal from the relay correct? or is this different from a standard automotive 5 prong relay?
 
Chacaro

Chacaro

Member
8
1
Costa Rica
Vehicle Model
civic Si
Body Style
coupe
Hello all,

Im not that good with the wiring and so on, but i really want to turn on the Fog light without using the headlights but i saw that the way was using an extra switch to turn on and off; is there a way on doing this using the factory switch?

Any help will be really appreciated, thanks
 
trustdestruction

trustdestruction

Well-Known Member
811
439
Tampa, FL
Theoretically you should be able to do the stalk method by changing the wiring on the relay so that it receives a constant 12V signal when the car is on, rather than a 12V signal that relies on the low beams being on.
 
trustdestruction

trustdestruction

Well-Known Member
811
439
Tampa, FL
Well, a relay works like this in general:

Most commonly I have seen they are 4-pin relays.

So logically, in our case we have the following for the relay:
  1. Ground
  2. Positive 12V output to Foglights - this is what the relay controls
  3. Positive 12V input from Power Source that will power foglights
  4. Positive input from the Switch - that will trigger the relay and complete the circuit inside of it sending power from #3 to #2 (numbers are for this example only)
So, the #4 is coming from the foglight switch on the steering column. It seems that on the other side of the foglight switch, the headlight switch controls whether or not there is even 12V going to the foglight switch to be sent to the foglight relay.
My guess is that you could easily get under the steering column, and then splice the positive wire that feeds the foglight switch into the 12V that feeds the low beam switch (or any constant 12V for that matter, but this is the safest/easiest method), which would bypass the foglight switch's dependence on the low beam switch.
 
hotshot

hotshot

Well-Known Member
663
314
trustdestruction said:
Well, a relay works like this in general:

Most commonly I have seen they are 4-pin relays.

So logically, in our case we have the following for the relay:
  1. Ground
  2. Positive 12V output to Foglights - this is what the relay controls
  3. Positive 12V input from Power Source that will power foglights
  4. Positive input from the Switch - that will trigger the relay and complete the circuit inside of it sending power from #3 to #2 (numbers are for this example only)
So, the #4 is coming from the foglight switch on the steering column. It seems that on the other side of the foglight switch, the headlight switch controls whether or not there is even 12V going to the foglight switch to be sent to the foglight relay.
My guess is that you could easily get under the steering column, and then splice the positive wire that feeds the foglight switch into the 12V that feeds the low beam switch (or any constant 12V for that matter, but this is the safest/easiest method), which would bypass the foglight switch's dependence on the low beam switch.
Click to expand...
Cool. Wanna test that?
 
Chacaro

Chacaro

Member
8
1
Costa Rica
Vehicle Model
civic Si
Body Style
coupe
Looks good, however should the relay go before the factory one right? so the circuit can be done before?
 
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