So I think I've got most of the wires connected for my autometer A?F gauge. Power on the red is coming from the car stereo power. The black is grounded to the ground for the CD changer which goes to the seat bolt. The white is connected to the gauge cluster dimmer switch on the continuous power side (red wire) Now I've read all I could find on HT about where I'm supposed to connect the purple wire to. Some say white with red stripe, of which there are two on my ECU and some say solid white wire of which there is one on the ECU. Now I have a 94 LS 5spd and none of the descriptions of the wire placement have matched up to what I've got. I've tried all three wires and got nothing more than one green LED on the rich end of it on each of those wires. I did change one thing since I tried all three of the wires and that was I moved the white wire's conenction off of the red/black wire and onto the straight red wire. On the red/black wire the gauge would glow when I turned down the dimmers and the light would almost go out completely when I turned the dimmer switch up to light up the gauge cluster. Any help here would be appreciated before I go back and pull the ECU out of its cradle.
Thanks in Advance

 

TTT can anyone help on this? I want to get the gauge hooked up tomorrow and get it done right

TIA

 

Just run it to the green wire coming from the O2 sensor.

 

Everyone seems to be saying to run the purple wire to the O2 input at the ECU instead of at the Cat or the header where the O2 sensors are. Something about the signal being cleaner there than at the actual sensors that and I'd rather not run the wires into the engine bay if I can help it.

 

run the purple wire to the solid white wire coming form the ECU, its the only white wire there

 

 

what the last two guys said

 

It's the white wire (said again to give you warm fuzzy feelings that it is the right wire).

 

All right, thank you all for the consensus. I do feel warm and fuzzy about the whole thing now. I will repost in an hour or so after the install is complete. Thanks to all.

 

as much as I appreciated the consensus of what wire to tap into at the ECU, my car does not appear to agree. Now i'm not even getting that one LED on the rich side to light up. I've checked all the connections and moved the ground to attach directly to the firewall but i'm still not getting any signal on the A/F gauge. It lights up when I turn on my headlights but that's all I'm getting from it.
any more suggestions?

TIA

 

OK, let's try this again.

1. Hook up the black ground wire to a known GOOD ground. Grounds can be a pain in the ***. Take your time and find a good one.
2. The red wire goes to a switched igntion source. The easiest place to find this is at the fusebox.
3. The purple wire connects w/ the ALL WHITE wire at the ECU.

Godspeed.

 

remember that you need to start up your car and let it idle for about a minute before you'll see any readings.

 

Good point.. the gauge should still "hunt" though when you turn the key and apply power.

 

Anyone have any reasons as to why this might be? If the reading were to change at all, would it not be cleanest/clearest right by the sensor? Just curious.

 

personal choice i guess, id rather have wires inside of the car than running them outside into the engine bay

 

I found out the hard way that running the power to the car stero was not a good idea. You need to run it to the fuse box! Just trying to save you a headache.

 

i hooked mine up to my o2 sensor. works great.

 

 

So last night I ended up driving home at about 3am and you know what, suddenly I'm getting a bit of a readout on my A/F gauge... WTF? Its giving me one red bar under about normal acceleration but I got up to the fourth bar lit while on an on-ramp. Still I doubt that the car's running that lean. I'm wondering why though I'd only start getting a readout late at night when the car's been out in the cold. Would that have something to do with it? I'm going to try and rewire the power feed to the fusebox instead of the stereo and see if that makes a difference and once more check the rest of the wiring. I'm not sure if its related but I've got the lighting for an oil pressure gauge also wired into the lighting wiring for the A/F gauge and that's not coming on either. Though I might need to wire the power feed for that gauge into the red wire instead of the white wire. hmmm...
Thanks to everyone for their help.

 

i hooked mine up to a white wire i thought was the O2 wire and was barley getting a signal then i went and looked around and found aother ALL white wire and tried that one and it worked
i also have a 95 LS

 

-Teggy I'll have to look again. I switched up the power feed to the turn signal fuse on the fuse box since that should always be hot when the car is on. But now I get like a big spike when starting up the car and then only a bar or two when accelerating heavily. couldI be hooked up to the alternator signal or something, could that be giving me some signal when under heavy load? Could it be that my oxygen sensor is f'ed up? I swear the car's running rich too which is not making me too happy when I can't even get the gauge to say I'm running lean...

 

It finally works!!! It wasn't the solid white wire after all. It was a white w/ red wire that went into a thick grey w/ pink wire that actually gave me a signal. But I see what everyone means about these gauges, they really don't tell you a whole hell of a lot... Oh well, at least I got the stupid thing working. not sure why I have a diiferent cable connected to my O2 sensor than everyone else.