O2 wires in harness wrong color??

[turp23]

I tried testing the wires for my O2 sensors at the computer and one is not the correct color. Number 29 was dark green with pink stripe and measured from .4 to .8 volts. Number 43 was dark blue with a green stripe and measured from 14.1 to 14.3 volts. Either one is bad, or one of the wires is wrong. Any advice?

 

[vristang]

How did you decide what color the wires should be?

Ford changed the wire colors over the years, and sometimes didn't wait for the new model year to change color....


My 90GT has 91 wire coloring....


jason

 

[turp23]

From wiring diagrams and replies from this board. If they changed the color, then what about the voltage? The readings I got cannot be correct. If they are correct, then one must be bad, right?

 

[jrichker]

The 14 volts is probably the O2 sensor heater voltage, the .4-.8 is the O2 sensor output.

Check the AutoZone wiring diagrams for some more input.

AutoZone wiring diagrams

http://www.autozone.com/servlet/UiB..._us/0900823d/80/16/71/3c/0900823d8016713c.jsp for 79-88 model Mustangs

http://www.autozone.com/servlet/UiB..._us/0900823d/80/19/59/5a/0900823d8019595a.jsp for 89-93 model Mustangs

http://www.autozone.com/servlet/UiB..._us/0900823d/80/1d/db/3c/0900823d801ddb3c.jsp for 94-98 model Mustangs

 

[Deleted member 87397]

Look closer at the wires. I had to look at mine multiple times even with the wiring pinout to find the correct colors. Looking at a pinout diagram would probably be better anyway since the corresponding pin should be correct even if you have a different color wire.

 

[turp23]

so if the pins are right, what is the voltage I should be getting? How can one be .8 and another 14v?

 

[turp23]

can anyone help me out with the voltage readings?

 

[vristang]

can anyone help me out with the voltage readings?

The 14 volts is probably the O2 sensor heater voltage, the .4-.8 is the O2 sensor output.

 

[turp23]

What does that mean? Are they good or bad?

 

[turp23]

Ok, lets try it this way. If the O2 sensors are good, what should their voltage be?

 

[jrichker]

Ok, lets try it this way. If the O2 sensors are good, what should their voltage be?

Here's a tip: the newer the sensor, the more the voltage changes, swinging from as low as 0.1 volt to as much as 0.9 volt. As an oxygen sensor ages, the voltage changes get smaller and slower - the voltage change lags behind the change in exhaust gas oxygen.

When the mixture is rich, there's less oxygen in the exhaust than in the ambient air , so voltage is generated between the two sides of the tip. The voltage is greater than 600 millivolts. Remember rich = more voltage.