My 2007 Prius came with a 1-CD radio and a 6-CD changer below it. The changer died and the radio got a knob snapped off, so I purchased a used 6-CD radio to replace both. Never in my wildest nightmares did I imagine that the radio wiring harness would be specific to the radio the car came with! The Gen 2 Prius had at least 3 radio options; possibly more. Why and where on Earth did an electrical engineer decide to go with a wiring harness that only connected to one radio?! Or did the 6-CD radio have an adapter / dongle between the 'base' harness and the connectors on the radio? I cannot even cut the 1-CD radio connectors off the harness and splice in the 6-CD radio's connectors because the used radio did not come with any external wiring (its connectors). Any suggestions, information, or assistance would be greatly appreciated. I allotted 10 minutes to swap out these radios. I'm already 10x over that expected time investment and have gotten nowhere.
I agree it's messy. Probably the best way to find out how messy it's going to be for you is to look in your wiring diagram: Toyota Service Information and Where To Find It | PriusChat and look especially for the wires and connectors shown with numbered asterisks. Those are the ones that are different between versions of the wire harnesses, and you'll see a legend on the page somewhere showing which option each numbered asterisk corresponds to.
