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DIY: Independent Foglight Mod

Old 02-06-2008, 04:05 PM
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Default DIY: Independent Foglight Mod

I stumbled across a few pics I took when I did my independent foglight mod a couple years ago. Saw nothing in the tech section for this so I figured I'd post it up...

This will work with B5 A4 model 1999 - 2001. Mine is a 2000. I am not sure about models > 2001 but I know it will not work for pre-1999 cars.

To do this mod - which permits using the foglights even though the headlights are not engaged, you have to modify a relay box that is plugged in up and behind your glove box. There are other versions I have seen that modify the plug that accepts the relay. But I'd rather modify the relay so that I can replace it if the mod ever fails. You will need to be able to solder.

1. Release the runners on side of the glove box door so that it will swing down toward the floor. There are two small spring loaded pins/bearing that you have to push at the same time. Kind of funky but not hard to figure out.

2. Then remove the end cap on the passenger side of the dash. When you look in you should see this (this one is not my picture). The relay in this picture has the 927508 code stamped on it:

You need to pull this relay box straight out towards the cabin to unplug it, then pull it from the opening pictured.

3. Once you have the relay out, you need to remove the box cover. This can only be done by releasing 1 clip on each of the four sides of the cover at the same time. I drove nails where the box cover meets the plug on each side to separate the clips. You will know what I mean when you size it up. Once all 4 nails were in, the cover released.

4 Grind down spades: you need to grind down or cut off three spade connectors that would normally send power to the fog lights. The circuit board assures that these spades only have power when the headlights are on. We will bypass these by removing these spades and then reroute the power from a constant source by soldering wires on the backside of the plug.

Spades to remove are #12, #15, #17

Now you need to solder (on the back side) pins #14, #15, #17. Notice #14 is the odd one out here. The wire shown below was temporary while I was testing the current. I later replaced it with a smaller gauge wire. Use soldering flux or the solder will never take.

Once you have done this, slide the cover back on the box, reinstall the relay into the car (which can be tricky) and you have fog lights independent of the headlights.


Last edited by brrman; 04-28-2010 at 11:17 AM.
Old 02-06-2008, 06:02 PM
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