Hi, I have a 1999 GMC Sierra SLE and I am trying to hook up an auxiliary input. Things are not looking good. I bought a PAC AAI-GM9. Everything connects just fine. Except when I toggle the input I get nothing. If I max out the volume on the stereo all I hear is a beep every second.

Does anyone have an idea of what might be wrong?

Thanks in advance.

Here are the details.... the factory unit has a cassette in the head unit. The head unit also controls a factory cd player. There is a 9-pin wire harness that connects the two. When the PAC AAI-GM9 is connected the CD player works. But when I toggle the input switch I get nothing. I returned the first PAC unit because I thought it was the problem.... Now I am not so sure...





-Jeff