So,
Ever since i installed the AVIC-Z1 about 1.5 years ago, i have been un-happy with the audio quality coming out of the system... No buzzes or anything for some time, just thought the sound and range was not up to par with my Alpine deck in my other car.... So, i changed the speakers (Infinity Kappas now). Things were a bit better, not great. Added a 4x150 Alpine Digital Amp....Things were better, but not great.... Added a Sub.... still was not happy...
After some time with the above setup, on occasion i would start to get alternator whine (not always)... So, i naturally assumed that my wiring was faulty (since it was intermitent).... Took everything appart and checked every connection for resistance and continuity and all checked out fine...
Lately, the entire left channels would go out together with the whine... One observation is that when the Parrot BT unit would cut-in, the sound would be fine and coming from both front channels as it should... with NO BUZZ.
So, i took the whole thing appart again this Saturday, this time all connections checked out again! (naturally)... but what i did was connected an RCA cable to one of the Aux Inputs and took the shield from the other side of the cable and grounded it to the chassis...
So, started the car and no whine ever since.... The added bonus is that not only did the whine completely stop, but the unit is dead quiet and my output levels seemed to have improved. Now the unit has much better transient response and overall much more musical.... Not quite like my Alpine deck, but WAY better (to my ears) than before...
So, my guess is that there is an intermitent connnection problem internal to the unit related to the ground....could be the infamous internal fuse, but not a blown-fuse problem, since i would expect that to cause the whine all the time.
It's been a few days, but hopefully it's been resolved.