Alright. I have already done the center vent mod and got the gauge to fit NICE and snug. However, I have come to the wiring portion of the install now. The gauge calls for four different wires to be connected. They are as follows: 12V Constant, 12V when Ignition On, Illumination, and Ground. My question is, does anyone have a copy of a 2001 A4 1.8T wiring schematic I can use to source these from a FSM or can you guide me to which wires I need to tap into. I want to use as little wire as possible to prevent problems in the future. Let me know if you can help... Thanks!

 

I know in the vent there's 2 wires that go to the vent's dial light it should be a +12, only when the lights come on, and there's a negative, my gauge has 4 wires too.. I just connected the +12 for the light and the negative. And i was done.. Do you have the defi link? If I remember correctly when my friend connected his in his Sti, he took power from his clock which is always on. Since our clock is in the cluster... You can probly tap into the head unit..

 

I actually have the Red Racer series... The Link would be simple since I would just have to power the unit itself. The gauge goes through the little start up sequence and re-zeros itself upon startup. This is more of a standalone unit than the Defi Link series gauges. Also, the two 12V sources have built-in inline fuses with them. I was planning on picking up the illumination source and ground from the two wires that run to the vent dial light and the two 12V sources elsewhere. I just needed a wiring schematic to make things simple for me. Thanks for the input!

 

I got a bunch of crap on my website you can check for a electrical digram there

Www.JC-mallozzi.com/audi

I think in order it's
1.8t atw
1.8t aeb
2.8 30v
2.8 12v then it should be easier from there

Edit: the above is for engine mechinalcal so u can ignore that

 

Thanks for the link JC! I do have a Hayne's manual for the VW Passat and Audi A4 with the wiring schematics in it, I just don't know how accurate they are since they give the same color wires for ALL Audi A4's and such... I might just be busting out the Voltmeter and proding around until I get something. Thanks again for all the help!

 

Did some probing around in the car with a test light yesterday. Think I might have decided on where I am going to get all of my wiring sources from. First I'm thinking to get my illumination from the red wire that runs to the center vents to light the dials up. Second planning to use the black wire that does the same for the center vent dial lights as my ground. Next I plan to get my 12V constant source from the red wires that are connected to the bottom of the relay panel under the knee bolster on the driverside. And finally get my 12V Ignition On signal from tapping into the wire that runs to the fuel pump from the fuse block. Do these spots sounds logical or am I just planning on putting myself in a world of hurt?