useless wire?

[tmj91]

I have found a white wire that goes thorugh the fire wall that connects to nothing on either sides they have connectors just no where to go. On the wiring Diagram off os sweptline.com it ios shown there without goin to any thing as well. My question what is th point of this wire?

[digdoug]

If I remember right,the factory tach uses a white wire.

[Jeffc]

What year truck???????
In and around 66 there are 2 white wires that
go thought the fire wall=
1))one for the brake lights>changes to black but will be un-used if you have turn signals because instead of
running through the fire wall it runs to the columm
on the cab side.
2)) oil sending wire for oil light. also un-used if you have the pressure gauge.

[tmj91]

67 sorry and no its not the oil sending light i have found it and its black counterpart