Ordered my D3 and have been snooping around this forum for info in preparation of doing my install. I will be installing this in my 04 F150 (new body style) I have read a few threads talking about a VSS wire but cant really figure out what it is and were it hooks up to on the HU, is it a wire on the OEM harness?? I should get it in a week so I just want to be ready.

TIA for any help you may be able to offer.

VSS is Vehicle Speed Sensor. Its output is proportional to actual vehicle speed. AVIC uses the information for dead reckoning i.e. estimating the position of the vehicle in the absence of GPS signals.

 

I don't think the wire will be on OEM harness. You will have to locate the wire yourself and tap into it. Same for reverse.