my original hu got bluetooth function that i can use for phone calls and music playback through my phone. but after installing amp i realize that there is no sound from the speaker whenever i make calls and play music in my phone. the bluetooth still connected, everything is working, just no sound at all.
at first i thought is the factory hu problem, so i take to warranty and replaced a new hu, but after changed still same problem, no sound.
wanna ask experienced installer here, what possible factors will affect the bluetooth sound? i sent to accesories shop to ask them check the hu and amp wiring they say nothing wrong. is there any other factors i should tell them to double check?
possible that installing amp will affect the bluetooth function?

ur RCA hi-low or ur processor are tapping from the rear spk output......

bluetooth as i know only output to front speaker.....

most oem hu is like tat

Means currently my bluetooth speaker wiring is connected to the rear speakee?
Is there any ways to correct it?