So I am looking to hook up my AVG-VDP1 to my head unit. The book says the standard power, acc, ground, however there is one extra I'm not so sure about.

Pink- Used to detect the distance the vehicle travels. ALways connect the vehicle's speed detection circuit. Failure to make the connection will increase errors in GPS locator.

Word for word from the manual, any ideas??
Head unit is an AVH-P5700

 

Pretty self-explanatory, but since you didn't bother to tell us year/make/model of the vehicle you're working on, we can't tell you where to connect the pink wire.

 

1995 Honda del sol

 

VSS Wire Yellow/White Speed Sensor at Transaxle, 3 Pin Connector

Pulses Per Mile 4000 PPM from http://www.the12volt.com 94

 

Great, thanks man ^ that link helps a lot.