SO I bought my Pioneer AVIC-F700Bt used. I had to get all the harnesses to go with it. I have not bought the one with the white plug that goes to the unit. It has the RCA plugs on it. Does anybody know if this is a must have harness? I was able to hook it up today, I do have sound and it appears that I have Navi. What is that other harness for?

that harness is for RCA's out to amps (front, rear, and sub), audio video input (av1 for Ipod ), and back up camera input. this harness also has the mute wire which is needed for the bypass (play videos and enter addresses while driving)

the unit will function with out it as long as you dont need to hook up a Ipod, backup cameras, external amps, or want to bypass the unit (the unit can still be software bypassed)

Thanks! ANother question: are there any other model AVIC's that have the same cable that would work? I know they mave have different part numbers but would say an RCA harness work from a Z1 or D3 etc? I need one.

im not 100% sure but i dont think they are the same as any other, i though i read that anybody that switched units from a D to a F also had to switch out all the harnesses, and that little guy isn't cheap either it like over $70