Wiring in 3 wire O2?

[85shelbycharger]

I just finished up doing the AIS and TPS wiring for my T2 conversion yesterday (very simple) and want to utilize the newer style O2 sensor with my setup. I have the plug for the new O2 I got from a junkyard. Can someone give me some directions on how to wire up the two new wires? Where do they go? Thanks!

[Tony Hanna]

What year/model did the plug come from and what are the wire colors?
I'm pretty sure the +12v feed for the heater comes from the ASD relay on the newer stuff, and the ground on a 3 wire is just the ground for the heating element, so anywhere would do. I'd put a ring terminal on the ground and attach it at the back of the intake with the ground strap.

[85shelbycharger]

What year/model did the plug come from and what are the wire colors?
I'm pretty sure the +12v feed for the heater comes from the ASD relay on the newer stuff, and the ground on a 3 wire is just the ground for the heating element, so anywhere would do. I'd put a ring terminal on the ground and attach it at the back of the intake with the ground strap.

The plug came from an '88 or '89 Lebaron I think. I know there's the black wire, a white one? and I can't remember the other.

[Clay]

1 wire is the signal wire
1 wire is ground
1 wire is +12 volts w/ key for the heater.

The factory taps into the large green wire in the injector harness to feed the heater. Shelby tapped into the blue wire in the solenoid harness to feed the heater.

When I did my 4 wire conversion I tapped into the green wire because it is a bit bigger, which will help with the load. Plus the factory way cant be bad. ;)

[Tony Hanna]

The plug came from an '88 or '89 Lebaron I think. I know there's the black wire, a white one? and I can't remember the other.

'88 for a 3 wire, '89 for a 4 wire.

I'm going off of wiring diagrams for this.

1. black wire. This should be the ground for the heating element. crimp a ring terminal to it and attach it to the bolt on the back of the intake where the ground strap is connected.

2. black wire with a dark green tracer. this is your sensor signal wire. It ties into the original signal wire going to the ecm.

3. dark green wire with a black tracer. This is the 12v+ for the heating element. It should tie in to the dark green wire with a black tracer coming out of the ASD relay. Alternatively, you can attach it to a 12v+ source that's hot with the key in the run position.

4. (If it's a plug for a 4 wire sensor) black with a light blue tracer. This is the sensor ground. For best results, ground this wire where your a/f gauge is grounded. The negative terminal on the battery is best.

edit: be careful not to get #2 and #3 mixed up. This will send 12v+ to the sensor and destroy it.

[85shelbycharger]

1 wire is the signal wire
1 wire is ground
1 wire is +12 volts w/ key for the heater.

The factory taps into the large green wire in the injector harness to feed the heater. Shelby tapped into the blue wire in the solenoid harness to feed the heater.

When I did my 4 wire conversion I tapped into the green wire because it is a bit bigger, which will help with the load. Plus the factory way cant be bad. ;)

I agree with doing it how it was done from the factory :thumb: What color wire did you tap into the green injector harness wire? And on that note, what injector harness did you use? Do you use the one that came off of the log T1 motor?

[85shelbycharger]

'88 for a 3 wire, '89 for a 4 wire.

I'm going off of wiring diagrams for this.

1. black wire. This should be the ground for the heating element. crimp a ring terminal to it and attach it to the bolt on the back of the intake where the ground strap is connected.

2. black wire with a dark green tracer. this is your sensor signal wire. It ties into the original signal wire going to the ecm.

3. dark green wire with a black tracer. This is the 12v+ for the heating element. It should tie in to the dark green wire with a black tracer coming out of the ASD relay. Alternatively, you can attach it to a 12v+ source that's hot with the key in the run position.

4. (If it's a plug for a 4 wire sensor) black with a light blue tracer. This is the sensor ground. For best results, ground this wire where your a/f gauge is grounded. The negative terminal on the battery is best.

edit: be careful not to get #2 and #3 mixed up. This will send 12v+ to the sensor and destroy it.

Ah, it seems you answered the question I had for Clay. So it will be the dark green w/black tracer wire that taps into the green injector harness wire?
Thanks for the tips, Tony!

[Tony Hanna]

Ah, it seems you answered the question I had for Clay. So it will be the dark green w/black tracer wire that taps into the green injector harness wire?
Thanks for the tips, Tony!

Right, It should also be a little bit heavier gauge than the black wire w/ green tracer.
Why they used 2 wires so close in color I have no idea. Really makes it easy to mix them up and smoke a sensor.:(

For the record, the wire I was talking about coming from the ASD relay probably actually comes from the PM on an '85 (I was looking at a diagram for a later model). It appears to be the same deal though. Feeds the injectors, fuel pump, and ignition coil. Same wire Clay was talking about but it looks like it should be dark green with a black tracer just like the one coming out of the plug.
HTH,
Tony

[john1320]

Good information here guys, thanks! I also own a 85 Charger, just finishing the t2 swap here as well. On the downside, just noticed that I have to convert to cable shift somehow. My rod linkage is right under the turbo swingvalve.:(

BTW, did you get a good deal on the EVO intercooler?
We used an SRT unit since it was dirt cheap atm, didn't even have to pull the nose off. :D

[GLHNSLHT2]

Throw the stock 1,3, or 4 wire in the trash. Get an LC-1 wideband and just feed the simulated NB output into the ECU. Much more accurate and you can tweak it if you want. A long time Turbomopar/shelby guru was looking at my yorker the other day. "You know your O2 plug isn't plugged in" LOL! Yea I know, the car runs better without it :) But I gave in and showed him the wideband setup.

[Michael_Valentine]

I know this is old, but I have a Mopar 3 Wire Sensor that I plan on using on my 86 Daytona with a 1 Wire Sensor. The new Sensor has 2 White wires and one black wire. Anyone know which one is which? The white ones are solid white, no lines or anything. Same with the black one.