I'm hooking up an autometer air/fuel gauge in my 93 and I can't remember which wire is the signal wire on the oxygen sensor harness. Anyone remember which wire they used?
Use 43 (Dark Blue/Lt Geen wire) or pin 29 (Dark Green/Pink wire ) on the computer. Use Wire tap-ins from Radio shack P/N 64-3052. The computer is located under the passenger side kick panel. That keeps you from having to crawl under the car and make a weather proof splice in the wiring. You can use either one, or run a SPDT switch and use both. Then you can use the switch to select which side to view.
See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host)
The A/F gauges that use the O2 sensor signal will jump all over the place. The reason is that the O2 sensors "switch" between .2 volt lean and .6 volt rich with a curve that looks like the drop off a high cliff. The curve is almost straight up and down, so the voltage shoots from .2 to .6 and back down . again 2 or more times a second at cruse. You won't get much useful information except when the mixture is extremely lean or extremely rich, there is no middle ground.
I hate to tell you but the gauge really doesn't do much since it is not a wide band(I have an autometer one). I wouldn't depend on it to tell you more than to tell you that the car is on or off. If possible I suggest returning it and getting a wide band or any number of other gauges instead...
Kevin
So even if I use the pin setup I will still have a gauge that just jumps all over? Mine in the 92 only reads a constant reading while accelerating. At idle it goes from nothing to rich about once every second or two. Is this normal for a autometer air/fuel? I had this pro comp ultra lite air/fuel just sitting around, so I bought a fuel pressure gauge to go with it. I didn't just want one gauge on the pillar. My boost gauge is above the heater controls alongside an oil pressure gauge.
Without trading the gauge and sensor for a wideband setup, all you are going to have is a pretty but useless light show.
The O2 sensors switch from rich to lean and back to rich. That's part of the design. That's also why O2 sensors are only about $40 each rather that $150-$300 for a wide band sensor.
Mine always says lean... It is really nothing to judge how your car actually is running. Get an aftermarket water temp, oil pressure... anything but a non-wideband A/F gauge.
Kevin