I just got done installing my new AVH-P4000DVD. Everything seems to be working fine, but when I took out the factory unit there were 2 harnesses and the antenna plugged in to the back of the factory. However the new headunit only has one harness and the antenna. This is all I was sent with the dash kit to install.

What is the other harness for, I read in my manual that it was an electrical harness. Everything seems to be working, I have not hooked up the parking brake sensor for the dvd or the rear view camera. Does anyone know what the other harness is for and if it will effect anything? Thanks for any help

 

The second harness is probably for the factory subwoofer. Is the OEM subwoofer installed in your truck?

 

I do not have a factory subwoofer. The harness is in the Haynes manual and it seems to be generic to all models. I still cant figure out what the harness is for, the manual said electrical but I dont know what it is supposed to do.

 

Can you take pictures of the rear of the stock headunit and the harnesses you are talking about? Maybe someone will be able to recognize it and give you some guidance.

 

was the second harness in use on your old stereo or was it just stuck to the side? I know on my truck there is a second harness back there that doesnt do anything and I thought it was for steering wheel controls or something if equipped.

 

So far everything is working properly. I was told that the harness was for steering wheel controls, however my FX4 doesn't have any steering wheel controls. I am not sure if all F150's are wired for the steering wheel controls. Also the harness was plugged into my stock radio. I will post some pics sunday or early next week because I will be out of town this weekend.