View Full Version : Air/Fuel Guage ?Signal Wire?

05-27-2003, 10:01 AM
Ok Fellas,

I just finished reading the previous post on which wire to use when hooking up the Air/Fuel Ratio Guage. However, I am a little confused. On my guage there is a lavender wire that needs to hook upto the signal return wire in the O2 harness. However my chiltons & a haynes I looked into doesn't show which wire that may be.

On the previous post people were saying the 'Black' wire, but in my book that is showing ground. ..

I have a 92 SC, can someone tell me Exactly which wire I need to tap. I don't have a volt meter on hand.


05-27-2003, 02:49 PM
Ok now... I've seen many experts on this subject post in the last few hours... Someone should have this info. I can't seem to find a book that does.


05-27-2003, 05:46 PM
This is from the tech articles at the tccoa:

Because tapping off the sensors involves real heavy duty wrapped-insulated wiring (unless you grab further upstream somewhere), you can grab the H02S signals from anywhere (from either R or L or both sensors) thru the O2 sensors's 'signal' wires going to the PCM.

Just tap both Left and Right HO2S signal wires at the bundle-stalk connector in engine bay over by passenger side hood gas-strut shock, right behind shock tower and against firewall.It's a vertically-positioned kinda square-topped connector there. You'll see it.

Put some 18ga. taps there, then route in thru firewall (there's a huge -unused- rubber grommet at firewall just below -at that area also which comes thru up inside below the glovebox area but way up above carpet edge top area)

Inside, you'll need a 12v+ switched power tap (H in Start/Run), a ground, a light circuit tap w/grnd (and to be safe an in-line fuse along the 12v+ power tap).

Then you can grab a DPDT toggle to allow both L or R sensor or OFF monitoring

Once you've placed your toggle, it's on -with the wires to the A-Pillar where you'll route wiring and make connections to the A/F gauge and install your 1, 2, or even 3-gauge pod Pillar setup.

The A/F gauge (at least AutoMeter's Phantom line) has nice real tiny, thin gauge wiring (looks like 22 ga. or smaller wire size) that's all color coded that you can route down thru piller pod mount and into behind dash area, so you can meet your other wiring to solder connections and save 'sqeezing' any more wires than absolutely necessary.


Check this link also:

Good Luck,

05-27-2003, 11:02 PM
i just tapped in to the black wire on 02 sensor it works fine

you can also remove the pass side kick panel inside door under and beside glove box and tap directly at control module tan and orange striped wire goes to 02 sensor #1 and tan with redstripe wire goes to 02 sensor #2

05-28-2003, 10:11 AM
Jeff & rlong~ Thanks for the input. I'm going to put it to use tonight. .. Do you know if it matters which side is tapped into?


05-28-2003, 11:03 PM
i put 2 volt meters on one on each side they run fairly even i would say normal cruising voltage mostly goes up to .66 to .77 then goes back down in boost or wide open it goes up to .8 or .9 volts it never went much over .9 yet
i guess the voltage changes a lot because the computer is always adjusting when the oxygen sensor senses rich at .66 or .77 volts it then starts leaning out until its down to . 2 or .3 or so then oxygen sensor tells computer its to lean so it starts going rich voltage goes back up