Replacing nav in 03 ML500
 

My dads got an 03 ML500 with Navigation and bose sound. The Navigation is acting up so it needs to be replaced. A new unit is going to cost him over $2000plus install.

Is there an aftermarket Nav head unit that will work with the existing speakers and amps?

The factory system in that is closed loop fiberoptic meaning there isn't a useable audio path between the factory deck and factory amp. Secondly your speakers may be an odd impedance making them unusable with an aftermarket headunit (without distortion and sound quality issues)
His most cost effective option, if the rest of the system is fully operational, is to stick with the factory nav.
An aftermarket nav is going to cost you upwards of $1000 plus speakers and install so it quickly can exceed $2000.
There are benefits to doing so tho. First being modern updated software Blue tooth interface and aux hookups and other convienient user interfaces secondly is sound quality. The exsisting speakers are over 7 years old constructed from poor quality materials and are near the end of their user life as well as the rest of the electronics.
Most factory soundsystems generally don't last ten years befor problems and your dads is showing signs of that.

ya factory stuff is garbage


but cleaner looking than aftermarket deck

:(