Hi.......I've installed an electric aerial into my car (the original ford one) and am using 2 SPDT relays to reverse the motor (up/down). So with the radio off the antenna goes down and with the radio on the antenna goes up. I'm using the original car switch to do this. However, when the aerial fully extends or retracts I have to hit the switch to cut power to the unit otherwise the motor keeps running (not nice!!). So the question is what should I use to automatically turn power off to the antenna at full height or when retracted????? This function is normally controlled by the high series BCM (Body Control Module) - my car has the mid series.