While I am fairly mechanically inclined (or so I thought), I can't seem to figure out how to connect my new HU. I am replacing a 2010 GMC Sierra 2500 radio non bose, w/o Onstar with a Pioneer AVHP3100. Pioneer came with a harness and I bought the Scosche GM22R adapter harness to make it as easy as possible and not lose all the 'safety' features that GM decided to wire through the radio. I am basically just connecting the free leads from Pioneer's harness to the free leads on the Scosche harness, both have instructions, but I am still confused. I hooked up all the obvious ones and the ones where both directions matched and I am left with these colors and their descriptions: On GM22R I have left: Violet/White - VSS Speed pulse signal (A/C voltage when in motion) Red/White - Reverse Light Trigger (+12v when in reverse) Yellow/Black - Parking Brake Trigger (-12v when park brake is on) Orange/White - Auto illumination Blue - Powered Antenna Orange - Illumination On the Pioneer I have left: Orange/White - Lighting switch terminal Violet/White - Of the two lead wires connected to the back lamp, connect the one in which the voltage changes when the gear shift is in the R position. This connection enable the unit to sense whether the car is moving forwards or backwards Yellow/Black - Mute Light green - Used to detect the On/Off status of the parking breake. Lead must be connected to the power supply of the parking brake switch. The above descriptions come right from the instructions for each harness. What do I do with the rest of them? I just don't know enough about this stuff to start guessing, and I don't want to have to undo it once it's done. Thanks in advance for helping me out. I have posted this same question in a couple spots hoping for some experts to chime in. I am hoping to get this done today so I can have a radio for the work week. Greg
