Motorola radios using 16 or 20 pin rear accy connector pinsTX radio pins:Pin 2 Mic Hi (audio in) (WHITE to pin 11 IDOM4)Pin 3 PTT active low (GREEN to pin 3 IDOM4)Pin 7 Ground (BLACK to pin 1 or 12 IDOM4)
RX radio pins:Pin 7 Ground (BLACK to pin 1 or 12 IDOM4)Pin 8 COR (active low is default for IDOM4) (BLUE to pin 7 IDOM4)Pin 11 discriminator audio out (YELLOW to pin 8 IDOM4)Pin 13 +12 vdc (this is where IDOM4 gets its power) (RED to pin 2 IDOM4)