Originally Posted by 370_o

I just ran into the same problem as the OP with my Alpine head unit install this weekend. I had to rearrange the pins as previously suggested to make my Metra wire harness work. I'm not sure where that connector diagram previously posted came from but my vehicle side harness, and the service manual I was using, didn't have pin 18. Fair warning to all out there, Amazon is still selling bum connectors.