Speed signal wire location - Hey guys. Installing a new head unit in my 2006 Sierra WT and need to know where the speed signal wire is. Am replacing the ...

Hey guys. Installing a new head unit in my 2006 Sierra WT and need to know where the speed signal wire is. Am replacing the basic AM FM radio with a Pioneer AVIC unit that comes with navigation so the current harness is pretty basic. No Bose or Onstar to deal with. If someone knows the location and color code on the wire it would be a big help. Thanks.

Hopefully this will help you out...

Car Speed Sense Wire: Green/White
Car Speed Sense Wire Location: In Harness on the Drive Side of the Engine Compartment

Forgot to add...It is pin A4(4th from the end

ELDiablo wrote:Hopefully this will help you out...

Car Speed Sense Wire: Green/White
Car Speed Sense Wire Location: In Harness on the Drive Side of the Engine Compartment

There are three visible wiring harnesses on the driver side of my engine bay. Only one harness contains a green/white wire ( harness is located on the firewall next to the left of the brake booster and appears to be connected to a relay or blank connection ). In any event the green white wire is not in position A4 of the plug. What am I missing ?

Try this..

Speed Sense dk. green/white 4K instrument cluster, pin A4 or PCM


The PCM (Powertrain Control Module) is in the left front of the engine compartment to the left of the fan shroud.

On gas models, the VSS wire is in the green plug, pin 50.

On diesel models, the VSS wire is in the black 58 pin plug, pin 42.

Also found at the radio harness, on some models

This site should have all the info you need...http://www.the12volt.com/installbay/veh ... d/GMC.html

Got a green/white on the instrument cluster (could be green yellow but it's in the right spot ) so that look's like a winner. Plan is to remove the A4 female lug, solder lead wire to it and replace it in the harness plug itself as I hate spliced wires. Thanks for the help.
While you're on a winning streak, any thoughts on a convienient source for switched power ? Radio needs both and as near as I can tell the harness in the truck does't have it. Just let me know when I use up my three wishes and I won't bug you anymore.

Hope this helps

[quote="Chasmanian"]Hope this helps[/

Pics worth a thousand words. Thanks, that confirms what ElDiablo described and what I located as a result. At this point am looking for a convienient source of switched 12v power. Any suggestions would be helpful. Is it necessary to use one of the more expensive wiring harness' that are available for the 2006 model year work truck ? Am using a simple harness only and am thinking that may be causing me more trouble than it's worth.
This install is proving more challenging than I thought. Head unit I'm installing is a good deal longer than the stock unit and less wide to boot and the cheap plastic double din install kit I found is pretty much useless on this Pioneer unit. Had to modify the rear support bracket for the stock radio a good deal to get the new unit to fit and will be looking for a more robust dash install kit once I get the wiring sorted out.

Metra makes a good kit for your truck. You should be able to grab a switched power source at your fuse box.

Also on most the pioneers you can get by with not hooking up the speed wire.

Lots of good info here http://avic411.com/

You can also look for these wires.