I have an Aux input unit that is trying to read an open/closed circuit on roller door motor to confirm that door is closed and display on shac interface. Circuit is working fine when contact closed but when Circuit is open it still reads between 5 mohms and 12 mohms and aux unit sees this as a closed contact and won't switch. I was of the understanding that it only needed about 1000 kohms to read open circuit. Any suggestions would be greatly appreciated Ash