I just installed a new JVC KD-AVX77 in a 2000 Mercedes SLK230. I retained the factory Bose amp and used a harness from Metra (70-1786) with RCAs built onto it. The only other wires I hooked up were Ign, Bat, Gnd, Ill & Amp turn-on.
When I turn the uniy on and select sources, I get popping through the system. Also when I use the phone. I suspect it's a ground issue, but I'm using the ground that operated the OEM unit. I'm confused.
Any help would be greatly appreciated!