3 wire o2. I have a 4 wire plug. 1 wire harness.

[85_600]

I'm going to be doing the T2 soon and would like to know what's needed. The car is a 85 600 with the 1 wire O2. I have a 3 wire sensor (thanks Greedy) and a 4 wire plug.

What would I need to do to get these together Is it just a ground? I've read The Dodge Garage and TD.com for ideas but nothing "definative" has been found.

Any ideas?

Thanks,
Paul

[87glhs232]

You have a 4 wire harness side plug? Why not go with a 4 wire sensor then? Much cleaner signal ground.

1 wire = signal wire only

3 wire =
signal wire
heater +
heater -

4 wire =
signal wire
signal ground (direct to battery is best)
heater +
heater -

If your car is one wire, then you need to add a 12v key switched and fused circuit for a 3 wire sensor (for internal heating element). For a 4 wire you need to add the same 12v circuit as a 3 wire, PLUS an additional ground for the signal circuit.

[85_600]

I was asking for donations for my project and Greedy had a spare 3 wire sensor just laying around. $5 and it was mine. I was hoping that converting the 1 wire plug to a 3 wire wouldn't be much trouble, then I started thinking about converting the 3 wire to 4, hence my question...

Isn't it possible to just splice the 4 wire plug into the harness using spare wire, possibly running the new wires to the LM and grounds and such?

[87glhs232]

Now I'm confused. Do you want to run a 3 or 4 wire sensor?

This thread at TD helped me convert 3 wire to 4.

[85_600]

Now I'm confused. Do you want to run a 3 or 4 wire sensor?

This thread at TD helped me convert 3 wire to 4.

You're confused What about me? I'm the one with this stuff

No, really. I have a 3 wire sensor. The Dodge Garage says 4 wire is the way to go, so, I'd like to know how much work is involved converting from 3 to 4 wire. That's all. How would a 3 wire sensor be modified to plug into the 4 wire plug.

I hope that's a bit better...If not let me know. Maybe I can confuse you and me even more

[tryingbe]

Just use the one wire that is already in the car.

[SpoolinGLH]

if your going to convert to 4 wire then whats the point of using a 3 wire o2 sensor? To answer your question , Its not hard at all to convert. Just make sure you use clean grounds and a 4wire o2 sensor lol

[85_600]

Hmmmm...maybe I shouldn't have bought the 3 wire then? I thought I could just add the 4th ground to it to make it 4 wire....Heh, stll learning I guess..

[87glhs232]

Oooohhhh, I think I get what your saying. You can't convert the sensor it's self. A three wire sensor is only going to be a 3 wire sensor. You can't mod the sensor it's self to make it 4 wire. You'll need to get a 4 wire sensor, or convert the car for your 3 wire sensor.

[85_600]

or convert the car for your 3 wire sensor.

Yea...That's the ticket!

So, is this relatively easy?

Right now I have a 1 wire sensor. I do have a 4 wire plug (spare one) if that helps.

Now I'm getting on the right track...

[87glhs232]

4 wire plug wont help unless you have a 4 wire sensor. At this point, you have 3 options.

Best:
Buy a 4 wire sensor, and splice the 4 wire harness plug in as described above. One 12v circuit and an extra ground.

Good:
Find a 3 wire harness side plug, add the two wires for the 12v heater element circuit, and splice the 3 wire harness plug to the factory 1 wire and the new 12v circuit.

Meh...OK:
Cut the plug off of the 3 wire sensor. Hard splice the signal wire from the sensor to the one wire on the car. Then run the 12v circuit for the heater element and hard splice those to the sensor.

One guess as to what I would recommend. BTW...if you don't want the 4 wire solution, I'll lift that harness plug off ya