1995-2002 Range Rover P38A
Maybe the problem is with your Nav unit rather than the DSP amp? Could be holding down the mute line or something? Have you tested with the nav unit unplugged?
I wish there was a "Like" button!Ya know Tom, Chris is dead on. You are purchasing old used amps. You have to wonder why someone would be selling these amps. If you are buying from a breaker you know dang well they have never fired up the radio in a car they are going to part out.