# Which wire on the O2 sensor is the signal wire?



## 89VWdieselGolf (Feb 22, 2004)

I'm pretty sure its #1 in this pic, but wouldn't mind a second opinion.








installing a/f gauge.
thanks,
Jeff


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## dan0954 (Mar 4, 2009)

*Re: Which wire on the O2 sensor is the signal wire? (89VWdieselGolf)*

This link may help. His was green, but he said it should be black.
http://faculty.ccp.edu/faculty...x.htm


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## 89VWdieselGolf (Feb 22, 2004)

*Re: Which wire on the O2 sensor is the signal wire? (89VWdieselGolf)*

thanks got it http://****************.com/smile/emthup.gif


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## capsolo99 (Dec 29, 2006)

*Re: Which wire on the O2 sensor is the signal wire? (89VWdieselGolf)*

how about the pre cat o2 sensor...i have this mess and dont feel like soldering all the wires...just the one that sends the signal...little help. Just wanna know which one it is...such a mess


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## 89VWdieselGolf (Feb 22, 2004)

*Re: Which wire on the O2 sensor is the signal wire? (capsolo99)*

well..
1) yours is OBD2 where as the plug i showed was OBD1
2) you need to fix all the wires, not just the signal wire because you dont feel like doing the rest. two are power and ground.
3) We already discovered the one on its own away from the other 3 is signal


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## capsolo99 (Dec 29, 2006)

*Re: Which wire on the O2 sensor is the signal wire? (89VWdieselGolf)*

well....
thank you for the information. I know the 1st one was obd1 just kind of expanding on the topic title. Thanks


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## dan0954 (Mar 4, 2009)

*Re: Which wire on the O2 sensor is the signal wire? (capsolo99)*


_Quote, originally posted by *capsolo99* »_well.... thank you for the information. I know the 1st one was obd1 just kind of expanding on the topic title. Thanks

That's the wiring harness side isn't it? Do you have any pictures of the other side? I don't have OBDII either, but from what I can understand and I could be wrong is 1 is ground 2 are for heating power and 1 is for signal. But it seems as if you are missing a whole wire as I don't see it in that mess.


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## capsolo99 (Dec 29, 2006)

*Re: Which wire on the O2 sensor is the signal wire? (dan0954)*

yeahhh I haven't even tried to get down there. So I am going to get some pictures when I have the time to clean out my tb. I'm just confused if there are 4 or 5 wires in the sensor.


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## dan0954 (Mar 4, 2009)

*Re: Which wire on the O2 sensor is the signal wire? (capsolo99)*

Well looking at the picture I can see where you might think 5, but the O2 sensor only has 4. If you look closely at the picture, you can see the Brown one has a rib in that spot. It sure looks like a rib in the black one also, just chewed up.


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## sgolf2000 (Mar 2, 2003)

*Re: Which wire on the O2 sensor is the signal wire? (dan0954)*

i would cut one from the junk yard and splice the whole thing. that _is_ quite a mess.


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## capsolo99 (Dec 29, 2006)

*FV-QR*

thats what you get when you let a retard mechanic work on your CEL


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## dan0954 (Mar 4, 2009)

*Re: Which wire on the O2 sensor is the signal wire? (sgolf2000)*


_Quote, originally posted by *sgolf2000* »_i would cut one from the junk yard and splice the whole thing. that _is_ quite a mess. 

X2


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## capsolo99 (Dec 29, 2006)

*Re: Which wire on the O2 sensor is the signal wire? (dan0954)*

unfortunately...the sensor and it's wires and clip are all intact. it's the wires from the harness to the clip that are royally fudged up....
so bad that Ill have to cut into the harness to get enough wires to connect to the clip. Thats why I need to figure out which ones are which because i'll be having to wire up the female clip.
does that make sense?

Harness wires ---BROKEN---E D------- O2 sensor (everything intact)


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## dan0954 (Mar 4, 2009)

*Re: Which wire on the O2 sensor is the signal wire? (capsolo99)*


_Quote, originally posted by *capsolo99* »_unfortunately...the sensor and it's wires and clip are all intact. it's the wires from the harness to the clip that are royally fudged up....
so bad that Ill have to cut into the harness to get enough wires to connect to the clip. Thats why I need to figure out which ones are which because i'll be having to wire up the female clip.
does that make sense?

Harness wires ---BROKEN---E D------- O2 sensor (everything intact)

We understand that it is the harness side, so when you go get another connector do not cut just a short piece. Cut into the wiring harness and get extra wire. 

I have a big question and I'm not sure if I can word this right. Look at your picture real close. See that crimp connector that looks like it's almost pointing to the brown plug. You can read AWG 21-18 on it and then a yellow wire is cutting downward to the right. Is that connected to anything? 
I seem to be able to track every wire but that one and at the connector where the wire is broke is yellow also. I hope you can understand what I'm thinking. Well here is what I'm thinking, I think that's the broken wire.


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## MK2SnowPilot (Sep 8, 2005)

*Re: Which wire on the O2 sensor is the signal wire? (sgolf2000)*


_Quote, originally posted by *sgolf2000* »_i would cut one from the junk yard and splice the whole thing. that _is_ quite a mess. 

X3
And a tip I picked up from my mechanic you made his own o2 sensor test piece. Should also work as way to make air/fuel gauges "plug and play" without touching the original wire harness!
When you are at the junkyard:
1) Cut the end off an o2 wire harness that is the same style as your car
2) Cut the end of o2 sensor that mates with #1
3) Crimp them both up into a third 4 hole connector 
4) Feel free to disconnect the o2 from the harness, insert test piece and plug o2 sensor into test piece. Then you can multimeter the o2 sensor output or power or ground while the car is running








Now the best connector to splice too would be one that your multimeter or air fuel meter plug connected to snugly. Buy a new one so you can crimp / soldier the wires into the plug.


_Modified by MK2SnowPilot at 1:40 AM 5-22-2009_


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## capsolo99 (Dec 29, 2006)

*Re: Which wire on the O2 sensor is the signal wire? (dan0954)*


_Quote, originally posted by *dan0954* »_I seem to be able to track every wire but that one and at the connector where the wire is broke is yellow also. I hope you can understand what I'm thinking. Well here is what I'm thinking, I think that's the broken wire. 

That wire is broken. That yellow one is the one that should be attached to the last wire on the plug. It's disconnected at the plug and chewed up on the other side
I believe the yellow wire is the signal but I'm just going to get the jazz at a junkyard and try and spend a while on it. Watch me fix it and end up having a bad o2 sensor


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## dan0954 (Mar 4, 2009)

*Re: Which wire on the O2 sensor is the signal wire? (capsolo99)*


_Quote, originally posted by *capsolo99* »_
I believe the yellow wire is the signal but I'm just going to get the jazz at a junkyard and try and spend a while on it. Watch me fix it and end up having a bad o2 sensor









By the looks of the first picture and the picture at GAP, my guess is that is the signal wire also.


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## capsolo99 (Dec 29, 2006)

*Re: Which wire on the O2 sensor is the signal wire? (dan0954)*

word. thanks everyone for all of your ideas! If i had the need to it would be an excelent time to add a fuel air meter. But I dont have the need


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