Audio Systems: No Radio Sound?, sony cdx m8800, mercedes a class

Question
Hi, I have just bought a Merc A Class that came with a sony cdx m8800. CD works fine but I do not get any sound from the radio? pulled unit out and seems the antenna lead is connected but no sound. cant find any info in manual or on the net, any suggestions would be greatly received. Thanks, Bryan

Answer
Hi Bryan,
I too have a Mercedes A Class, a 2001 A170 CDi Elegance auto with Becker audio 30 ASP sat nav., (as well as a 1987 2.3-16v cossie .-) so I know the car very well. no amps are fitted as standard.

The Sony should have standard ISO DIN connectors as does the car so any modern radio plugs straight in, one for the power and one for the speakers, the antenna lead would make no difference to the radio not making a sound, you would still get a hiss and even a local strong station without the antenna. If the speaker connector (8 leads) is in and the phone mute wire is not grounded it should work.
DIN connections  are.
Speakers

Right rear -,  right front -,   left front -,  left rear-,
Right rear +, Right front +, left front +, left rear +

Power block viewed from cable side

Phone mute (white or yellow),/   n/c, /      ariel & amp (blue), /ignition (red)

N/c, / 12vlive, (yellow or orange), / lights, (various colours),/ negative (black)

The third, usually top, block is for accessories such as cd changers

Good luck and let me know via feedback please.
Peter