What is the correct power cable for my lcx 18c .I have a grey power cable withe two small cables. One small cable says speaker and is black and red with no shield. The other small cable has 4 wires, blue, orange, yellow, and shield. I have a extension cable for my LGC-12w module. It is plugged in middle connector on unit. When I turn on lcx-18 I get "module not responding. How do I check it out
GPS - Lowrance - LCX-18C