I was told that by a Biketronics representative - if I buy the radio and Biketronics kit from Biketronics, they will pre-wire and test everything prior to shipping. I ended up purchasing my kit from Dennis Kirk and radio from Best Buy, so that is one possiblity why there is a difference or perhaps it has to do with the age of the bike. Mine is a '90 and has a different Biketronics kit that the newer bikes. I am not sure of the difference, but do know I had to solder the Biketronics leads to the Sony plug. Either way, he will need the Sony plug if he buys a used radio.electra boomer said:The Sony deck I got (CDX5710) came with the pigtail and it was plug and play. No wiring to mess with. The Biketronics unit (Retro Radio) just plugged in. You shouldn't have to do anything as far as wiring.