Re: Aftermarket HU to factory amp adapter (yekat)
It looks to me that the VO03B will allow you to replace the HU-803 with an aftermarket HU--without the oem amp.
If you want to keep the oem amp, PA-200 or 300, you will need another adapter, like
this, to connect the oem amp to the new HU.
Keeping the oem amp, you will only need to use 1/2 of the VO03B, the green iso plug IIRC; the grey iso is for the speaker connections which are are connected directly to the harness from the aux amp.
Don't forget to disconnect the battery, if you are going to disconnect the CCM when you remove the HU. Also, you will need a software download when you are done to tell the car that it no longer has an HU-803--it is part of the CANBUS network and will throw an error code otherwise.
And, you do know that you will lose your steering wheel controls unless you get the appropriate Dietz adapter? (Google these forums for "Dietz steering" and you will find plenty of references; ss60 is the maven for this application.)
The oem HU & antennas are a diversity system (two antennas, the HU selects the strongest signal). An aftermarket HU and Scosche VOAB will only connect to one antenna--be sure it's the window antenna.
And, the question that I should have asked first: "why do you want to replace the oem HU?"