I really like the Audi like daytime LED running lights and would like to add them to my Crossfire. Rather than digging for the ignition wire it appears that I can purchase and automatic switch which you simply connect to the positive and negative of the battery and also to the running lights. Can someone please explain how this automatic switch actually works?

 

No need for that, there is a ignition switched terminal along with a always hot terminal at the rear of the under hood fuse box.
Just add a wire with an inline fuse for the DRL's.

 

Like George said (ala-xfire), just find an iggy activated 'Hot' in the under hood fuse panel (south of the DS wiper mounting point under the hood). You might be talking about a 'relay' that is controlling a lighting system but you can make it simpler (not even using a relay) if A) Your LED DRL's are of a real low current type, and B) You find that iggy controlled 'Hot' that is not being max'ed out when that circuit is fully in use. That 'relay' controlled 'Hot' usually is almost a non-issue if the circuit you use to supply the relay with is of a size higher than a 5 amp fuse or higher. Remember that relay coil of the type you would use uses a real small amount of current, but it can switch a load through those contacts as high as you can possible put in without getting real crazy. I like the really old wise saying known as KISS (Keep It Simple, Silly), if the 'load' (the LED DRL's) are of a high current/light output then use a 'relay' to control the high current supplied from a higher 'main' that is available elsewhere (and remember to properly fuse this tapped 'Hot'). If they are a design of low current, it'll be simplier to eliminate that relay and just use a portion of an iggy controlled circuit that has an excess of current that you can 'tap' into the excess, for that additional optional mod of LED DRL's.. In the end, please remember to document this modification, so the next owner (if one) can either 'undo' or repair any problem with it. Have FUN!

 

As the owner of a 2011 A4 2.0T MT6, your DRLs will look fine but they won't do the cool Audi trick of turning off the DRL (LEDs)) on the one side when operating the turn signal.

 

It does, that IS cool... It is possible to install a system that would accomplish this but it would involve a lot of research and experimentation to get it right. Man that is a cool system though!

 

If possible could you be more specific as to where I would fine the "ignition on" hot wire? I have not went back out to the vehicle and looked but as I remember the fuse box is near the firewall on the passenger side. Is the hot wire in that box and if so, can you give me a clue as to where. I can take a picture of the interior of the fuse box and post it if that would help.

 

The Battery is on the far right passenger side in left hand drive (LHD) vehicles, then next towards center is the box containing the RCM, the ECU, and a couple other components. Then across to the other side close to center is the brake booster and outboard of that brake booster (last thing before the drivers side fender) is the rectangular black box under hood electrical fuse center holding the majority of the fuses for the various systems in the car. That rectangular box opens by squeezing the tabs on the top front of the box, and lifting that cover off. In there, on the inside of the cover, is the legend of all the fuse positions and what they are hooked into. Now that you know where this box it, I suggest you download the service manuals for the car and research what circuit you might want to 'tap' into. I would limit the search to accessory items like the seat heaters, motors, and such. I would not tap into any critical engine management or safety airbag/brake power lines or systems. This is where your research of the type, current requirements and accessibility to the wiring coupled with the car electrical systems and locations of easy access for where you want to tap in. As a minimum, you have to at least know where all the basic systems and fuses are located, and which ones to stay away from. If you have any reservations about researching/looking up the info you need, then zip to one of the bi-yearly tail of the dragon meets and ask around for a little assistance. You can also try to meet up to one of the many XF tinkerers located near you. I am sure you can find someone who can assist you in accomplishing what you want to do. Good luck in your research and modding! Oh, also, you definitely have to start downloading a few of the .pdf's from the site. I recommend the first one be the service manual, and study it relentlessly.

 

As GG said above, you remove the TOP cap that has all the labels, then you can remove the cover under that to see the 2 metal terminal strips at the rear of the box.
One of those is "always hot", and the other is "ignition switched".
You will see a nut on each holding wiring connections, tap into the desired one with a wire and a ring terminal of the appropriate size.

 

Schematics are here...

documentation/Service_Manual.pdf

Download it first. Makes it easier to navigate.

 

Pics in this thread...

https://www.crossfireforum.org/forum/645463-post21.html

 

Just a quick note to say thanks for everyone for the help and especially to Syfi for all the detail and the pictures. With all of your help I expect this project to be somewhat easy now that I don't have to reinvent the wheel.

Just for the heck of it point your browsers to Hot Reduce Car Light LED DRL Relay Harness Automatic on Off Dimmer US Seller New | eBay and see what you can make of this thingy on ebay. If it works like they say it would be pretty neat but I have my doubts about it consistently working. Are they just assuming that there will be more voltage to the battery when the car is running than when it is not and the extra voltage would trigger it? Anyone got any ideas?

 

That's what I figure too. With the white wire connected to the low beam positive, it dims. ( didn't know that LED's dimmed too well ).
It has to be measuring the 12.x to 13.x voltage to work, and like you I am not too sure about the reliability.
It is CHEAP though at $13 with free shipping, so what do you have to lose ?