I'm currently installing the module and there are 4 wires, but only 1 is where my question lies. In the schematics, is shows the DGRN/RD going to the amplifier, but does it serve as a remote on or what? This thread didn't mention it. FYI, I didn't have to modify any wires to connect to the defroster. It might be due to the defroster ends look differently (all solder joints) than in that thread.