Alternator Whine issue with new headunit. Please help me troubleshoot!

[JuBu]

Ok, I tried troubleshooting my alternator whine once again today since the weather was actually nice outside. The whine is audible on radio, cd, auxiliary mode on the headunit. As soon as I turn off the headunit, the whine is gone, so it's definitely an audio and not a mechanical issue.

I have tried grounding the headunit to (1) the factory radio harness ground, (2) a chassis bolt under the dash and (3) the alarm unit's ground wire. All three make no difference whatsoever and the WHINE is still audible.

I put back the stock headunit and there is NO WHINE with it. At what point should I start thinking there may be something wrong with my headunit versus just being an issue of finding a better ground? Should I be thinking of maybe returning the headunit?

Thanks,
Justin

[Eric]

do you have amplifiers, or just the headunit? brand? check the antenna connection

[mydumpthatch]

if you still hear the whine, it means your subs arent hitting hard enough

[EastCoastE30]

I had the same problem and took it back to the shop. They told me that it wasn't properly grounded and fixed it. I know you already checked that but it's just my .02