Originally Posted by ctuna
Isn't it not good to be running speaker output channels from an
aftermarket head unit IC amp into a Hi Fi amp inputs as a preamp signal.
I would think the possibility of that happening is low just because the pins for the low level output of the hi-fi HU probably differ from the speaker level outputs of the base HU. If anything, I think VP is right that the amp is not turning on or there is no preamp signal going to the amp.