93 G20 audio system problem (factory amps a problem?)

[Matthew Bromberg]

Hello,
I had a friend of mine who installes car stereos fo a
living install a 15" alpine woofer and RF punch amp
into my 1993.5 infiniti G20.  Everything is hooked up
right, all components tested but still no output...
I've heard that the problem might be with the two
factory amps that came with the vehicle that year, and
that they may need to be rewired... if anyone has any
information on this I would really appreciate some
assistance, thank you
brom4176
Fredonia, NY