another where does this wire go?

[redneck23ms]

i'm trying to figure out where this wire goes. it goes to a sensor on the drivers side of the block. it is wrapped up along with 2 other wires. those 2 wires go into the plug for the sensor and this one is just hanging out all alone. anybody know where it might go?

[comanchedude]

Looks like the knock sensor wire, there is a water temp sender and knock sensor that run down to the driver side of the engine together the one you have in the pic is the knock sensor

[redneck23ms]

yes i know the plug goes to the knock sensor. but there is also another wire wrapped up along with the 2 wires for the knock sensor that is shown in the pic. that is the wire i'm wondering about.

[Ironwolf]

a spare one? :dunce:

[Geonovast]

a spare one? :dunce:

 

Probably...

 

I can't think of what that could possibly be for.

[ParadiseMJ]

Maybe someon was thinking they needed an secondary gound?? :dunno:

[redneck23ms]

the wire doesn't have insulation on it most of the way up through the foil wrapping. a guy on naxja says that its a ground for the foil wrapping. i guess its to prevent interference with the knock sensor signal.

[Wildman]

Wires that have a "foil" wrapping, and a bare wire are called "Shielded" wires, used in the electronic field. The bare wire is to be grounded, and the foil is just to protect the primary wires from interference.

 

The reply you got from naxja is correct.

 

Only one end of the bare wire needs to be grounded, the other end, like at the knock sensor, just wraps around the foil. In your case, the wire may have just came undone.

[gl1200aman]

In the service bulletin for the CPS wire update that wire is called "bare-braided knock sensor drain wire" and the other end is by the ECM. Appears to have been that way from the factory.

[Wildman]

Yes, as in this bulletin -

 

http://www.lunghd.com/Downloads_and_Lin ... update.pdf

 

 

See Figure 9.

[gl1200aman]

that is the one I have. Thanks for the link.

[kastein]

X2 on what wildman said - if you cut open a spare computer USB cable or similar, you will find the same thing. They do that because it is darn near impossible to solder well to the aluminum foil shielding, so they just stick a bare wire in next to it and solder to that instead when needed :thumbsup:

 

The things you learn as a professional nerd...

[fiatslug87]

Had the same question 2 years ago, now I know.

http://www.comancheclub.com/forums/viewtopic.php?f=2&t=12784&hilit=wire+knock