FM on radio not receiving strong signal, Volume low

[NorCal91NSX]

I had a broken antenna on my NSX since I purchased it over a year ago. Today I finally got around to installing a new one and it helped with the AM (seems to work fine) but the FM radio has marginally better reception at best. Also, at *full* volume it is very quiet. Any suggestions?? My CD changer works great and I can't come close to full volume while sitting in the car. Thanks in advance.

 

[NorCal91NSX]

Anyone have any ideas of what could be happening? Please, any help would be appreciated. There is also an antenna comming out of the rear glass that appears it could have been a cellphone antenna?? Thanks

 

[Hugh]

The defroster coils in the rear hatch also function as an FM antenna. The OEM tuner is a "diversity" type and will automatically select the best signal. It sounds like the antenna plug is not connected or at best not completely inserted into the back of the head unit. It is also possible the antenna cable could be damaged somewhere along it's length. There is also the possibility that the head unit is defective.