Hello,
I have a 2004 F150 XLT w/4.6 and tow package. the truck doesn't get driven every week. Please help with identifying this wire and how to get to it.
The engine light just started flashing when driving and mostly stays on but sometimes shuts off when idling. I found some rat debris on top of the intake/valve cover. I also found a cut wire while looking up from the ground just past the #1 bank forward o2 sensor. I pulled the passenger side inner wheel fender and took a picture of the wire. It looks like a 12ga. wire with heavy insulation. I can not find the other end or where the wire goes toward the center back part of the engine at the firewall and top of bell housing.
Thank you for your time and all information is appreciated.
JD from the generation 6 f150 forum.

 

Does the wire have any power (key on or off)?
Could it run to the O2 sensor heater circuit?
Could it be trailer power?

 

If it's solid black, it's a ground wire.

A single wire like that won't have anything to do with the trailer or O2 sensor circuits.

If you'd posted your fault codes, they'd probably offer additional insight into what's malfunctioning.

 

I had driven it on three occasions when this stared. each time po171 occurred and once po301.
I'm just guessing.
It could be the knock sensor under the intake manifold. Where is the wire loom that feeds the sensor?

 

Okay, is it or is it not a single, black wire? If so, it what I already said it is.

 

I believe it is a solid black wire.
to what and from what would it be grounding?

 

The wire is a small gage with heavy soft flexible insulation. I agree it is most likely a ground.

 

No additional accessories have been added outside of Ford dealer

 

Can you trace where it goes?

 

Probably between the grounding stud on the firewall and the starter motor mounting bolt.

 

I can barely get my hand on it. The location is at the top of the bell housing where it meets the block. I don't know what it is attached to. I will have to pull the intake to get to it.

 

Neither the schematics nor the manual indicate that there is a grounding wire in that location. Check the locations I gave you before trying to dissect the beast. You may just be experiencing a slightly unrecognized routing path.

 

I believe I found the connection. The harness conectton has a brown and a black wire to it. Please see the attached picture. I don't know what device or sensor that it goes to. All help is appreciated.

 

Took this picture from the drivers side of the intake.

 

also called intake tuner valve control ,really can't tell wire colors .