So I drove down to Jaycar and picked up one of their
12V DC noise filters
Installed it directly into the back of the stereo and ...
nothing
So I engaged the old gray matter and started thinking,
the high pitched whine is only evident when IGN is on
The high pitched whine is NOT there on ACC
So maybe it's an amplifier issue
Ahh, there it is
The filter is now installed onto the amplifier power line
Took the opportunity to vacuum the wagon and clean the filthy trim
Combined with mucking around with the settings on the headunit high/low pass filters
The annoying whine is isolated to the front and rear left speakers and is slightly less than the above video.
Small mercies.
I'd personally recommend Bundaberg Rum for this type of job
Need something much stronger than beer
And I will be indulging in a few, after I pack up the tools, clean the pool, scoop the dog shit ...
Ahh life
Hope you all have a good one
