So the pos wire goes to ignition, so that the gauge turns on when you turn the key. The black wire goes to ground, the purple wire to the O2 gauge (which I'll need help finding, I think I found it, looks like a thin pipe bomb sticking straight out of the exhaust pipe that aims downwards), and the white wire to a light source of some kind, like dash lights. I'd like to do it a little different, please tell me or post your opnions if this setup would work:



I realized I didnt finish the pic before I uploaded, the yellow text says "yellow wires (actually white) connects to some kind of light source, this is for the gauge to glow, so I chose the headlights so it glows when I turn on my lights at night.

I wasn't sure if the switch setup would work, but everything else should...

I'd love to install it like the instructions say, but when it comes to electronics I honestly SUCK, and removing interior components to tap into the ignition wire is not my forte. Same with the dash lights which is why I wanted to tap into my headlights wire like I did with my foglights, but I am not sure if I do this, my headlights will get dimmer and dimmer...? Please let me know if I'm headed in the right direction for this, I looked for How to guides everywhere but no pics dont help, especially if it isn't the same car as yours.

 

you shouldnt need the switch and you shouldnt run it off the battery (although you coud do it that way) run the positive to any switched 12V wire (i used the cig lighter since i dont smoke) you DO NOT want to tap your O2 wire in the engine bay as that is a sheilded wire you can get your O2 signal from a wire at the ECU under the carpet in the passengers side foot well im not sure what wire you want or what pin on the connecter it is i cant remember but im sure someone will chime in and tell ya

 

The cig lighter sounds like a good idea, where exactly did you tap into the cig lighter? Under the dash or right in the middle of the console itself? As for the ECU I could use some help on that... like what wire I'm looking for in the ECU for the O2 sensor, the color or picture on it? Anyone?

 

S4/S5? TII/NA/VERT?

I installed an A/F on my S4 TII. Let me know what you got, maybe I can help.

 

i have an autometer a/f guage, and i have wired mine 20 different ways and still cant get it to work, replaced 02 sensor, and tried another guage,

i have it wired like so, o2 sensor> into the stock connector into the harness then connected in with that is purple wire from the meter, then meter is powered drirectly from battery, and black wire is grounded

the meter will not move or dance around at all, If the stock connector that goes into the harness behind the tb is connected the meter will read full lean, but if i disconnect it and just have the meter ran strait to the o2 sensor it reads full rich , ,,, but no matter what the meter will not dance around whatsoever, if im on the gass or not.... Please help me, i feel like a total dipshit

 

Yeah, that would help It'a an '88 N/A. I guess the main thing I need help on is finding the right O2 sensor wire that goes into the ECU, once I find it. I'd like to keep the idea of a switch unless I can find the cig lighter's wire easily, but like I said me and electronics don't mix at all.

 

Hey driftseshrx7, don't feel too bad at least you know your way around the wiring pretty well and seems you can read instructions good enough, also

 

drift your taping the wrong wire at the ECU ill try to find mt FSM and figure it out for you guys

and 7th i taped the cig wire at the lighter itself do you have a multimeter? if so just prob around there with it till you find a wire that get 12 V with the ignition turned one and nothing when you turn the ignition off

 

http://www.apexi-usa.com
http://www.apexi-usa.com/documentation.asp
donwload any pdf install manual, like apexi turbo/auto timer
and you know where to tap from there
that's my ecu wiring surce

 

Wow, that helps a LOT, thank you Tri.

Now to get to the ECU while being careful enough to not unplug anything.

 

By far the easiest way is to make all connections at the ECU, where you can get power, ground and signal. Tapping in the O2 sensor's shielded wire frequently causes problems.