[guruerror]

Plug the rear stereo controls back in and test...I'm pretty sure they have to be connected, at least to get rear audio with an aftermarket head unit. They won't actually DO anything, but they just need to be connected.

Also, I was 'advised' (by a tech at Crutchfield...years ago) that while the factory head unit is in and running, you should center your Fader and Balance and turn your rear volume all the way up (using the controls on the rear-seat panel). I guess the Bose amp stores some balance/volume info that an aftermarket unit cannot access, so this balances everything out.