I've taken the rubbish non-standard radio/cd out of the missus 2001 fabia & put in a brand new factory symphony radio/cd. Unfortunately, the radio didn't work before, & it still doesn't now, which rules out a problem with the head unit. There is a very faint radio signal on high volume. Is this an aerial problem? Any ideas from anyone would be appreciated.

sounds like an aerial problem , i assume you plugged in the aerial at the head unit , if so i would check the connection at the aerial itself , might involve dropping the head lining down though , i'm not sure if there are any other connections between head unit and the aerial base