I have looked at a couple different d3 installations and they have this in some of there pictures,

what is this for?

 

It helps the Nav track your speed to see how fast your moving, hence speed sensor.

 

ahhh i see

 

would i be feesable to use a wiretap to connect it?

 

i didn't even tap mine in. not really needed

 

what do u mean not really needed?

 

as long as you have signal from your sat then you don't need to hook it up. its not necessary

 

Awesome good to know

 

yeah if you read the manual all 400 pages of it you do not need to slice it in..........it will learn where you are without it.............

 

umm the speed sense helps with the accuracy of the navi and does the vehicle dynamics on the pioneer units. without the speed sense you may have problems with the accuracy where a clear view of the sky isn't always available.

 

or if you go through a a tunnel it will keep the navi on track...

 

lol I was going to say that but just figured ppl would say "how often do you go through a tunnel" either way I install these things and know that the speed sense wire is highly important to the full functioning of a navi