2008 Hummer H3

Electrical problem
2008 Hummer H3 V8 All Wheel Drive Automatic 24,400 miles

Am installing and aftermarket NAV unit and need the loction/color of the VSS (speed sense) wire. The ca does not have factory Nav, so It doesn't seem to be in the factory radio harness. Where can I tap into the VSS for the add-on NAV unit? Thanks
August 25, 2009.

There is not a VSS circuit, it is all done through a communications buss. I don't dabble in aftermarket audio, but I have seen some installations that have an interface module installed, that may be what you need. I would quiz an aftermarket installer, and see if they can provide you with some information. The factory schematic is the same for radio, or nav, and it has the buss circuit involved. The base system probably uses speed info for speed dependant volume, whereas NAV would use it for that, and GPS calculations.

Aug 28, 2009.