I installed the boss alternator kit, and since then my car has a moaning whine (heard particularly at idle) that matches engine revs. I believe its coming from the factory sound system (I need to pull the fuse for it as there's no easy way to turn it off since sync remains active with audio off). Its a constant volume noise.

Any thoughts on what I should look for?

Additionally, the only alterations to the factory sound system are two taps which run to the trunk for a infinity basslink II, and it is grounded to the chassis on the passenger side. Disconnecting that wiring has had no effect on the "whine/moan"

 

I can remember days long ago when a filter capacitor was required to remove "whine" in a radio, which was charging noise produced by alternators and picked up by the radio, creating a buzz in the radio speakers.

I would think the kit you installed whould have such a filter. This may be a question for the Ford engineers that made the kit you installed. How you'd get to them is the million dollar question though.

What does this alternator kit do exactly? Does it place "less of a charging load" on the engine?