Oxygen Sensor Connector

wtmeyer · 07-15-2004, 10:21 AM

Does anyone know where I can get a new connector for the Oxygen Sensor wire mounted in the enginer compartment. This is the connector inthe vehicle harness that the O2 sensors plugs into. It seems that some hack mechanic broke the connector while trying to diagnose an O2 sensor problem. The connector was hanging on by only a few strands of wire. I could probably solder it back on, but the insulator would still be broken most likely leading to a noisy signal. This is probably why I was having a cold start idle problem forthe first minute of warm up.

targa80 · targa80's Garage

I don't have any info on where to get the part for the connector. I did want to comment on the cold start problem. The O2 sensor is not used in initial starting. The Lambda unit runs in open loop and a thermal temp switch forces the unit into a 60% duty cycle. When the thermal temp of the switch is reached the Lambda unit goes into a 50% duty cycle. When the O2 sensor is stable and operating normally then the lambda unit uses the sensor signals to adjust the duty cycle depending on the signal. If you disconnect the O2 sensor you force the Lambda unit into the 50% duty cycle all the time after the termal temp switch has reached its set temp.

These comments apply to the Lamda system in a 1980SC. If you have an O2 sensor and a newer model car then I don't know how it would operate. I'm sure others will chime in on this topic.

wtmeyer · 07-15-2004, 10:41 AM

I forgot to mention that the car in question is an 83SC so Targa80 is probably correct.

ValveFloat · ValveFloat's Garage

How many contacts are in the connector? Three? If it is a two contact connector I may be able to help.

wtmeyer · 07-16-2004, 03:00 AM

It is the single contact type. There is only one large contact in the center of the receptacle.

fireant911 · 07-16-2004, 03:30 AM

My connector was broken also which apparently is quite common. My understanding is that the connector that the Oxygen Sensor connector plugs into is only available by obtaining another wiring harness which is not a very practical solution. I soldered mine back in place. The 'noise' you were referring to probably will not be an issue since this wire is shielded to prevent this electrical noise from disrupting the actual signal from the sensor. If you do solder this take your time and ensure that the soldered connection from the core wire is completely segregated from the other wire. A steady hand, some patience, and electrical shrink wrap is needed for this project. I do remember previously that someone on this board was recommending a co-axial fitting(s) for this particular issue.

wtmeyer · 07-16-2004, 10:00 AM

Thanks, Fireant911. I had not thought about changing both ends to a coaxial connector. That may be easier than soldering the old connector back on. The wiring was so mangled that I could not tell where the shield began and the signal wire ended. I have some slack in the harness. I guess I can cut it back a few inches to make a clean connection.

scottb · 07-16-2004, 02:17 PM

Can you get a connector from a "donor" car and splice it in to the existing harness?

sammyg2 · 07-16-2004, 07:22 PM

Go to http://www.pcaocr.org/pandemonium.shtml and click on June pandemonium download. There's an article near the end by Lee Rice (famous wrench and tech writer around these parts) that describes the exact same scenario you are dealing with, and how Lee took care of it. interesting reading. This guy knows his stuff, he's in the BA league.