I have a 2008 Edge Limited with Nav system. For the last several months, I've had the classic symptoms of the Nav screen going dead during use, or more commonly, when I start the car, the Nav system screen never turns on. Cycling power, disconnecting the battery, etc. all have worked for me for short periods of time. Now, I am fed up enough that I want to buy an aftermarket in-dash receiver. From reading threads here, it seems that it could be the APIM not the head unit (in dash touchscreen radio) itself??? If I buy a new receiver with proper wiring harness, and it turns out the APIM is bad, will the new receiver also not work? I don't want to drop $600 on a new radio only to find that when I connect it to the factory wiring it doesn't work. Anyone have any experience with this?