OK, I e-mailed
PIE with this question:
I just bought a 2000 Silverado and am looking for an auxiliary adapter for the factory head unit/cassette deck slave unit. What I want is an adapter that will let me do away with the cassette slave player altogether. I am hoping that this would be possible with the GM9-AUX. Other units I've seen for this setup require the cassette player to constantly be running whenever I would be using the aux in, I would prefer to be rid of the slave altogether. Is this possible?
And this was the response I got:
Yes, "RID" the Cass. and connect the GM9-AUX behind the radio.
Thank you for contacting
PIE.
I'm going to order it and try it. I'll keep you guys posted on it.