DIY Rear foglight

[bhbnuckle]

took me 1hr

[Gunman]

Finished mine up tonight.

[shirker]

This was mentioned earlier in the thread, but has anyone fixed up the rear foglight in such a way that it lights up if and only if the brakes are applied? I don't want the rear foglight lit whenever the front fogs are lit (frankly because I like keeping my front fogs on in the daytime, regardless of weather), but I can see it being useful as an additional brake light.

[shirker]

I guess a follow-up question to that would be, how are the taillights wired to get brighter when brakes are applied? Assuming the taillights are also (functionally) used as brake lights and get brighter when the brakes are on due to an increase in current through the same bulbs, is there a separate wire just for brakes?

On second thought, I suppose I could just tap into the third brake light. Any help would be appreciated! I've never modded a car in any form, but I'm more than inclined to tinker with my BRZ.

[kchkwan]

I did one of the group buy kits, not sure if my technical knowledge is enough. Though if you want the rear fog off and only on when you hit the break, shouldn't you just wire the rear fog to your third brake light rather than the original 2?

[boredom.is.me]

Originally Posted by shirker

This was mentioned earlier in the thread, but has anyone fixed up the rear foglight in such a way that it lights up if and only if the brakes are applied? I don't want the rear foglight lit whenever the front fogs are lit (frankly because I like keeping my front fogs on in the daytime, regardless of weather), but I can see it being useful as an additional brake light.

Originally Posted by shirker

I guess a follow-up question to that would be, how are the taillights wired to get brighter when brakes are applied? Assuming the taillights are also (functionally) used as brake lights and get brighter when the brakes are on due to an increase in current through the same bulbs, is there a separate wire just for brakes?

On second thought, I suppose I could just tap into the third brake light. Any help would be appreciated! I've never modded a car in any form, but I'm more than inclined to tinker with my BRZ.

Taillights operate on two filaments. In this case, the filaments are replaced by LED's but the same concept still applies. One wire gives the "dim" power when the headlights/fogs/whatever are switched on. The second wire powers the "bright" and only comes on when you step on the brake pedal. The third wire is simply ground. If you only want to use the lights in a brake-only way, you can do either of the following. The first option is to get a 7443 (dual) bulb and wire both the "dim" and "bright" to the wire that normally only provides power to the bright. The second option is to just get a 7440 (single) and run the "bright" to the positive led on the bulb. Simple I recommend doing the first option so you do not have to buy another bulb if you ever decide on wanting to either have a foglight or just a "dim" function when your other lights are on.

Originally Posted by kchkwan

I did one of the group buy kits, not sure if my technical knowledge is enough. Though if you want the rear fog off and only on when you hit the break, shouldn't you just wire the rear fog to your third brake light rather than the original 2?

See above.

This can all be done for $40. I used a 7443 18 SMD LED Red Bulb. You get the associated socket, wire it up, and you're good to go.

[zc06_kisstherain]

here's mine but i attached mine to license plate light using 194 socket adapter so there is no cutting or any type of modification to original wire. plug N Play

[boredom.is.me]

Originally Posted by zc06_kisstherain

here's mine but i attached mine to license plate light using 194 socket adapter so there is no cutting or any type of modification to original wire. plug N Play

So it's always at full power?

[zc06_kisstherain]

Originally Posted by boredom.is.me

So it's always at full power?

i didn't know there is full power or half power from wiring
it gets power from 194 socket.

[Gunman]

Any on found a good source of power in the back, so this light can function as an "on when the car is running" light? That way it would be like a rear DRL, and an additional running light at night.

[boredom.is.me]

Originally Posted by zc06_kisstherain

i didn't know there is full power or half power from wiring
it gets power from 194 socket.

You are asking for trouble if it really is always on "bright". 194 bases do not have dual input/power as far as I'm aware, so you probably are running at full brightness. Video?

[zc06_kisstherain]

Originally Posted by boredom.is.me

You are asking for trouble if it really is always on "bright". 194 bases do not have dual input/power as far as I'm aware, so you probably are running at full brightness. Video?

It's only on when parking light is on. basically when license plate light is on, rear fog light will be on. I don't think it will give me troubles. i have done similar to this to other vehicles in past and never had problems.
what's difference between mine and T-Tabing OEM wires that forum members do? since bringing power from same source.
if you can provide me more detailed info, it would be helpful since i am not that great with electrical stuff

[jacobzking]

I used the kahtec module which was super simple. after I pulled the lower light unit out of the car, i just attached the kahtec unit to the light (on top near where the 10mm bolt is) with some 3m double sided tape. the blue wire from the kahtec went to the + side of the new light bulb. i fused the black wire and the - wire of the bulb with a 12" piece of black wire and grounded it to the car (right above the muffler is an easy to see, easy to access 10mm nut sticking out. i just found a 10mm bolt and screwed it on to the wire to ground it. then on the red wire from the kahtec, i ran that through the grommet in the trunk on the left side (where all the other wires go, by the spare tire tools), ran that up to the green wire on the 3rd brake light and tapped it in. i spent maybe 2 hours total between finding wire, a light socket, removing the unit, dremeling out the hole and notches, disassembling the trunk, etc. i could probably do it over in about 45 minutes now that i know what to do.

[DrDuquette]

I don't know if this was said yet. But I would recommend putting the vacuum on the middle hole. Then blowing forced air through the backup light holes. When I blew air into the new hole. It blew the dust in between the red and the clear lens and now its stuck there. To fix my mess, I blew forced air through the side holes and got most of it out. Hope this helps. Thanks for the great DIY.