I have a limited 2003 4runner. I had a JBL upgraded system but it stopped working. Bought a Sony stereo. Went into local stereo shop and paid $190 for install. They said I needed a PAC adapter if I wanted my stereo functions to work. The unit alone was $109! Sound was cutting in and out. Took it back they replaced it and same thing happened. They called the rep from PAC and they told him 2003-2004 4runners have that problem. He said he disconnected 2 rca cables so the cutting in and out is fixed but I can't control the fade, treble or bass? What? So my question is, do I need the PAC adapter and will my stereo work without it? I know I got bent but any suggestions? Thanks.