Head Unit Grounding Question

Hi guys. I recently had my system professionally installed. Cosmetically they did a great job. Unfortunately, i have an awful alternator whine.  I have only had the system running for 1 wk yet i cant stand to listen to it because of the noise!!! aaaaaaggggggggghhhhh!

Anyway, i did a few tests. im certain that the ground loop is entering via the HU ground which is grounded up front through the original factory ground.  Im assuming this is through the wiring harness?? anyway ive isolated it to the HU ground because......

 1. I replaced the head unit (sony cdx c910) with new eclipse cd8443.  ground loop persists

 2. I patched my ipod into the eclipse via the AUX input.  same ground loop.

 3. i disconnected the eclipse rca output and directly patched my ipod into the line driver which takes the signal directly from the HU and sends it to the back into xover, amps over XLR cables!!!  Viola! the alternator whine disappeared.

Am i correct in believing the HU ground is the cause of the ground loop.  The remainder of the system is grounded in the back (3 amps, xover, etc).  I know install rule 101 says to ground all compnents to a SINGLE spot.  I am assuming that this includes the HU. Nevertheless, i am extremely disappointed in my installer.   1000$ install and i have alternator whine??? 

So, i rescheduled to have the installer go back and run a ground cable from the HU to the back where the ground distribution block is located. 

So what do ya'll think??    I am well aware that car audio is frought with noise but i feel they should at least ground the system properly .  Did they follow standard install technique and i am being too demanding???

^^Agree with the above comment, but don't spend any more time on this.  You paid for professional results, now go back and get what you need done before you mess something up.  The more you mess with it the more likely the shop will think you caused the problem.  You should have no noise in the system when all is said and done.  Except for the music source you choose to listen to...

You said that "install rule 101 says....", but believe me there is no such rule.  Grounding is sometimes a matter of trial and error because of the differences in each car's electrical systems.  The installler obviously didn't hear the whine or it wouldn't ( or shouldn't ) have been let out of the bay.  In a case like that you turn around and go back as soon as you hear it.

i appreciate the input. just wanted to make sure that whine is totally unacceptable for a professional install.  this was performed at a very well-respected car audio dealer in a major u.s. market.  they know better.  the manager acted as though i was putting them out. whatever. they got paid. they will do the job right.

thanks again guys!

Hear ! Hear !

                 - The Driveway Man