just installed a bluetooth handsfree in my ranger but the stock HU Am/FM /CD radio mute does not work on the radio when a call comes in Ford Part Number 4L5T-18C869-AE

So I found another HU to install Got it yesterday
For Part number 5L2T-18C869-BD
This unit has the aux and sat buttons on it as well

Listed as being in an 2005 Explorer Sporttrac
Same 16 pin power speaker connection
So the problem is I have no volume on the radio at all. everything else seems to work cd spins and changes channels clock sets .....
Display shows volume going up but nothing very slight static when up at max
What am I missing here?
Do I need to do something with the setup on the radio or what?
Did I just get a bum unit with the internal amplifier toasted?
From the research I did and the discussion with a radio shop this should work

Great Forum by the way lots of good info

RRII