Fog lights on only????

[PANCAKES!]

Hey guys I got a quick question. Does anybody know exactly how to rewire the fog lights on a "99 Q45 so that only the fog lights come on and not the headlights? I jus installed HID in mine and I would really like to roll around wit jus the fogs! Any info or help you may have would be great!
Thanks in advance!

[zion_97]

you will probably have to add a on off switch in your car and rewire them them seperate to do that..I want to do the same thing but have not got around to it yet..good luck!

[Caoboy]

i know on the ls400's, you could tap the signal wire on your fog light relay to a 12v constant hot wire so that you could turn the fog switch on independent of the lights being on.

if your fogs are set up so that you have a fog switch on the stalk, then you can probably do it.

you buy some wire, spade connectors (male AND female) and pull out the fog relay.

take those spade connectors and wires and make an extended 'harness' to plug in your relay.

tap the signal wire on the 'harness' with a T-tap or just splice it in so it's connected in the middle of the wire.

run that tap wire to an always hot fuse. stuff it in there, or if you have a separate spot for extra 12v constants on your fuse panel, plug it in there.

done.

all YOU need to go do is find the relay, and test the wires to figure out which is the signal, and make that harness.

it took me about an hour, and that was mostly finding which relay was the foglight relay, and getting to it/putting stuff back together.

if you tap it to a wrong hot wire, it will probably blow the fuse, so be careful. if it doesn't work, you could always just tap it to the parking lights signal, that way they come on with the first click. (looks better IMO, and you have your taillights on which you won't get in trouble then)

[REV-01]

it depends on your factory headlight/foglight circuit. i did some where i need to bypass at the switch. some i have to rewire the relay side.

[menappi]

Yea you'll need to wire the fogs u to their own switch with relays.

[{-.-}]

I wired mine to the parking lights and w/ a switch I can turn them on or off.

[excluesiveonez]

why dont u add a switch to the headlight, so u turn them off if the fogs will only turn on if the headlights are engaged?

[Caoboy]

why dont u add a switch to the headlight, so u turn them off if the fogs will only turn on if the headlights are engaged?

i don't get your post. can you explain it better?

the way i said to wire it up, is so you can still use the stock foglight switch. instead of having the headlights on be the signal for the relay to allow the foglights to work, the relay is 'hot' and fog's can turn on with the stock switch independently of the headlights.

[KickEachVerse]

i would love to have that function for my ls400

[Caoboy]

you can! i did it on my first gen.

[hahajoey]

i did it on mine.
i rewired it slightly so i can use my factory switch
which is located ON the turnsignal lever.

i relayed it so that it would get power from the parking lights
to tell the relay to give the ballast full power from the battery.
and i used my factory switch. so i guess to keep things simple.
i can turn on my foglights when my parking lights are on ONLY.
and if i turn off the switch they'll be off. if i put my lights to auto,
they would all turn on like they did factory.

i did this by checking the wire schematics on the column to
know which wire is what, spliced into that wire for the foglight turn on,
and used the factory switch as a "switch" grounding one end to the car.
so it would complete the circuit on the relay.

[TipStylez]

^Think you could get more into detail? Like what color wire into what ect?