Hi there!
I have problems with my s2 rst and fm radio, headunit wont find any stations. I did check coaxial cable disconnecting and short circuit from the head unit and then measured from the rear of the car and it was okay. Next i did change the antenna amplifier unit but still nothing.
I measured 2 wires which connects in the amplifier unit. Colors are red/white and blue/black.
I tried to give direct power to red/white + and blue/black ground but nothing. From the car there is no any voltage in those wires.

Do someone have schematics how that amplifier unit should be connected and how the polarity.