Bought a Pioneer double din and what I thought was the required wiring harnesses. Only the top two are compatible. do you have to have all four of the harnesses hooked up or just the top two? All I have are the top two and nothing works. I unplugged the bottom two from the bose to try and diagnose the issue but the bose deck seems to work with the bottom two not plugged in. what gives? help me out guys...

 

Are you using a LOC?

 

When I installed mine it only used the top two. The instructions for mine stated this. This also means that if you have the navigation system, the voice will no longer work through the car stereo. I have not found any wiring kits that use the navigation voice plugs.