I have a 96 b5 a4 with the integrated fog lights in the headlights and was wondering if there is a way to do a "fog light mod" so that I could run just the parking lights and fog lights because I am doing all HID's in my car and the fogs are going to be a different color than my headlights. If someone could tell me or get me the link to the post of how to do it that would be greatly appreciated. Thanks guys.

 

There are DIYs on www.audidiy.com and www.audiworld.com that can walk you through it. It doesn't always work though - I followed the switch rewire to the letter with no success on my 99, as did another member on his 01.5 - didn't work for him either. The relay mod should work much more consistently. There's a DIY for that too.

 

thanks for those tips, but what I am really looking for is to be able to run just parking lights and fogs. Has anyone else done this? and if there is a DIY for this could you please post the exact link for it? I cant seem to find any.

 

Those DIYs - last I looked - were intended to give independent operation of the fogs (ie, not requiring the low beams to be on). They should do what you want.

 

ok, i cant seem to find that one. would u be willing to find it when you have a couple of minutes and post it on here for me please. it would be greatly appreciated.

 

This turned out to be a long post, sorry.

First of all, there is something everyone should understand about the fog light mod. The relay mod ONLY works for facelift cars - that is, '99.5-2001.5 (or cars with fogs mounted on the bumper).

In order to get fogs to activate independently from your low beams in a pre-facelift car, you MUST rewire the switch. Why? The fog relay is not the same at all; in fact, it isn't even located in the same place and is much more analog in nature. The change between e-code and American lighting schemes is in the wiring in this case.

If you happen to have a facelift car and want your fogs to work independently of your low beams, chances are that nowadays if you go to the dealer and ask for a new relay, they will probably give you an e-code relay and your fogs will work like you want (which is comical). If you want it free, you can do the mod and cut/jump some pins. The change between e-code and American lighting schemes is in the relay in this case.

These methods will ALWAYS work if done properly on the right model year...

Devil, with all due respect, in pre-facelift cars there's something that you did not perform... you also have to completely remove the fog light relay and jump the connection with another 15A fuse... It won't work unless that is completed.

When you jump it, there are some other side effects. Your original fog light mod intentions will work prefectly, but your low beams and fogs will also stay on with the high beams which can be annoying or desirable; however, it's the only way to make it work...

I'm not sure what overall goal you are trying to accomplish, OP. You have posted some things which disturb me a bit.

First of all, I would advise against trying to run your fogs as makeshift 'low beams', as they are not directing light in the proper direction for night driving, so just wanting two different 'low beam' colors at night should be out of the question. If you want to have your fogs on during the day, OR when it is actually foggy, then that's cool with me.

Second, everyone on this forum is probably under the assumption that you are not going to actually put HIDs into your Bosch reflector housings. They all are assuming that you just want an independent fog light mod for your new e-code one piece or two piece S4 projectors. If that is the case, you will no longer have fog light bulbs AT ALL; you will, however, have some low wattage daytime running lights (DRL) which aren't HID, and do not really put out any visible light. This will be the case unless you purchase new fog lamps and mount them on your bumper.

Third, putting HIDs in a pre-facelift car with the Bosch reflectors is illegal and won't even put out as much light as halogens, believe it or not (your car will just be annoying to others and provide less light for you). Putting HIDs in a pre-facelift car will, in fact, eliminate any possibilities of having fog bulbs integrated in your headlamps because none of the projector housings have this feature.

I just don't know if you have thought this through all the way.

Personally, I am a fan of the Bosch halogen reflectors, which is probably contrary to the views of every Audi enthusiast forum in existence... but that's another story.

 

Awesome info Brian, thank you. I didn't pull the fog relay. It wasn't in the DIY that I used but I didn't think it through. Thanks again for clearing it - if you don't mind, I'll combine your info with the DIY and post up a new DIY in the forum here. It should clarify the process for anyone else who, like me, just plain didn't carry it fully through.

Time to get back after this and set it up

 

The fog relay is in either slot #7 or #10 depending on which model year you have (one slot will be empty and the other will have the relay).

Jump the left and right connections together with a 15A fuse and leave the other 2 ports disconnected, they have no function other than keeping a better hold on the relay in the slot.

Also, you need to be careful when cutting one of the wires to the center of the switch - there is no way to tell if you got the actual low beam signal or just the connection from the front fog switch to the rear fog switch. If you cut the wrong one you will end up with no rear fog signal and your front fogs will still be dependent on the low beams. I guessed wrong on the first try and had to reconnect it and cut the other line :|

The best way to tell is to cut one of the wires and try to use your fogs regularly. If they work - you got the wrong one... reconnect the wire and cut the other and splice it with your new connection.

You don't have to cut any wire on the bottom of the switch unless you want to operate the rear fog separate from the front fogs, but if you choose to, it's the same deal - you have to choose the right wire. To test this, cut one of the bottom wires and try to use your rear fog without the fronts turning on... If the fronts turn on with the rear, you cut the wrong one. I don't mind having the rear fog activate the fronts, so I left it connected. It also provides me with one less connection from the front fog switch to the rear fog switch - one less connection to accidentally fail... lol

 

Ok Brian, seems to be that you know your info, but i just have one question for you. Why are HID's in regular housings illegal?
If you are telling me that HID's in non-projector housings are illegal, could you tell me why these listed vehicles have HID's in non-projectors stock, from the factory
1) 2002 to 2007 Cadillac Escalade
2) 2005 body style toyota prius
3) 1998 body style Mercedes Benz E-class
4) 2002/2003 Nissan Maxima
These were all vehicles that came with/available from FACTORY HID's without projector housings.
Just doing my research and thinking everything through as you said I should do.

 

Those cars you listed with OEM non-projector housings were designed that way. Notice how the majority of HID equipped cars have projectors? It's because they perform better. Designing a non-projector HID housing saves money, but it does not perform better.

Regardless, the oem halogen housing in the A4 was not designed for HIDs and at the very least does not have the correct shape. There's pics all over audizine, audiworld etc adnauseum showing how terrible HIDs look in oem A4 non projector housings. Huge glaring hot spots, light scattering everywhere and it will blind on comming traffic. If you want a ticket, this is one of the fastest ways to get it.