Finally got my Speed of Sound gauge pod installed, water temp gauge and Raptor shift light hooked up. Now I just need to get my A/F gauge hooked up. Instructions say NOT to hook it up to the wire going to the O2 sensor, but instead hook it to the same wire in a harness somewhere. The wiring harness that all four of the O2 sensors wires come from runs across the top of the transmission and is impossible to get to. So my only other ( and more desireable ) option is to find that harness in the engine compartment, locate the wire in quesiton and splice it in there.
Does anyone know what harness and wire I need? I have seen the wiring diagrams from the service manual DVD. Kind of useless. According to the DVD, practically everything going to that harness connects to a red/yellow wire. :bang: I am pretty sure that is not the case! It is easy enough to see where the harness comes up in the engine compartment, but it almost immediately joins in to a main harness. So if anyone knows where I could pick up the wire I need perhaps at the power distribution block or the PCM, the info would be greatly appreciated.
Here is what Ford has for a wiring diagram.
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I can't help you one the wiring.

But I do have to ask: What is the point? You will NOT get a A/F GAUGE using the signal from the stock O2 sensors. Their output is so non linear that the only thing you can derive from them is a "lean of stoc, rich of stoc" information. And that is how the car's computer uses it: swings it rich until the sensor says rich, then starts leaning it until the sensor says lean. That is also why the computer doesn't use the O2 sensors for full throttle. It can't because you want the car to run richer than stoc.

A true A/F gauge will require you to install a wideband O2 sensor and it will connect to that. They cost more. But they actually do what they say they do.

 

You are correct.

The point you ask. Well, to be quite frank about it, the point is because I had these two gauges and I needed to put something in the 2nd pod.

 

That is an answer I CAN understand! Good luck getting your wiring straightened out.

If you just need the signal from one of the front O2 sensors (don't use the rears. The cats will COMPLTELY jack up the signal!), you may find it easier to pull the connector off the sensor under the car and then tap into that lead down there. It will be a pain, but you should be able to get it done with a bit of work and a lot of cussing.

 

Perfect for hawgman...

 

Only problem with that is, as I stated in the original post the instructions say NOT to hook it up to the wire going to the O2 sensor, but instead hook it to the same wire in a harness somewhere.

 

Maybe what they mean is don't hook it to the wire between the connector and the o2 sensor but to the wire on the harness side of the connector. The reason may be because newer o2 sensors breath through a slightly oversized casing on that part of the wire and vent through the connector. This is a reason for not using grease in any o2 sensor connectors.

Go to; http://www.autotap.com/articles/Understand...en_Sensors.html

Great article