centerpunch

NO GUARANTEES, PERFORM THIS MODIFICATION AT YOUR OWN RISK

I wanted to use my fogs as DRLs, but occasionally wanted to be able to switch them off. After much studying of the wiring diagrams, I developed a mod so the Fog Light switch works without the headlights being turned on. This mod is done to the wiring behind the fog light switch and rear defroster switch. You do have to remove the radio to access this wiring. (I was installing a new radio, so I had easy access.)

Attached 4-page pdf (link below photo) has full details.

Now the fog light switch will work whenever the ignition key is on.

For DRL use, just leave the fog light switch pulled to the "on" position, and fogs will come on automatically every time you start the car.

I did this on my '95 C4, it works great.

(Note- a separate circuit turns the fog lights off when the headlight high beams are on, if you also want to defeat that, details are in this old thread.)

If your fog lights are scratched and discolored, a source now sells separate lenses. It's a bit of work to refinish the housing internals and replace the lenses, but it's worth it. Details in this recent thread.

BTW, I tried several LED replacement H3 bulbs, they were all a total joke.

goofballdeluxe

FYI, for those with Canadian spec 993s, DRL came standard on them, and they act as your photo above illustrates.

Nice mod!

will007

Great information. My 993 was initially a USA car, then imported later to CAN. Fog lights work separately as DRL. Now I know what to look for in terms of how it was possibly modified for CAN. Thanks.

Greg Bell

Don't know what the local laws are but here in Australia you can get fined for having fog lights on if there is no fog.

centerpunch

There may have been laws like that in a few states, but now that so many cars have DRLs no one notices vehicles running with fogs on.

Chuck W.

Great mod and outstanding write up. Thanks for taking the time to put together the PDF. I just completed it without issue following your instructions. Many thanks.

centerpunch

berni29

Hello Paul

Yes, and thank you. I have a new radio arriving next week and while I am there will carry out your modification.

All the best and thanks again

Berni

kkswow12

germany... who woulda thought...

centerpunch

As I said earlier, I can't imagine anyone knowing or caring in the US.

These days virtually all cars have daytime running lights, and these are a good substitute for those...

HalfGerman

Here in the US there are plenty of BMW, MB, Audi and others that drive with their rear fogs on at nite and they haven't a clue.

My dad once told a lady at a gas station driving an Audi, her rear fog light was on, her reply: "oh I don't know what all those buttons are for so I just turn them all on".

Harold

centerpunch

As far as the rear fogs, I have those wired as additional brake lights with Tore’s kit.

https://www.bergvillfx.com/products/...conversion-kit

RockstarBruski

Great mod! If I ever pull my radio I'll think about doing that mod. 100% of the time when I drive any car I turn on the headlights and taillights as it makes me way more visable and hopefully will save me from people hitting my car or pulling out in front of me. 😀

Also my two Volvos have a setting to automatically turn on the headlights and taillights to always on day and night whenever driving. I wish more cars had that setting and not just a nighttime sensor setting as I see too many cars driving during dark and/or rainy conditions with all of their lights off because they've set their car to autosensing lights and their car doesn't turn their lights on correctly yet their inside dash lights are on so the driver thinks their headlights and taillights are on when they're not! 😞

centerpunch

Eight years later it’s possible that there are now H3 LED bulbs that are ok, might make sense to try them.

Although the normal halogen bulbs work fine and last a long time.