Anyone install the Z1, and have tremendous alternator whine when using the Onstar phone while the engine is running?
Anyone find a fix?
During the install, I created a new ground point at the crosscar bean just inside the dash. After install and noticing the alternator whine, I went back behind the radio, and ran an 8-gauge wire from the ground point I created directly to the battery ground terminal. Still have alternator whine.
I then encased the wires in a shield case (the wires from the NAV to the adapter were directly over the Onstar Module. Didn't do a thing.
Anyone figure this one out?

What interface did you use? I've seen it happen in the past and most of the interfaces tell you what to do to reduce or get rid of the noise in your situation.

Peripheral adapte for GMs with an amp and Onstar, along with the Peripheral Chime module.
Nothing in their directions about this problem. Not sure if it is the adapter.

That's a new one, you can try swapping the interface out could possibly be something wrong inside the module. Aside from that I don't really know what else to say short of trying a different brand interface.

I've encountered this a few times. Of coarse I tried swapping interfaces first, but this didn't fix the problem. The best solution I found was putting a good quality power noise filter on the consant power wire between the vehicle's radio plug and the interface. This removes most of the whine.