Single wire power/signal system for vehicle auxiliary devices

Abstract From the Canadian patent

Abstract of the Disclosure, Both power to and detection signals from a remotely located condition monitoring device are provided via a single wire with return through the vehicle frame. A load switching circuit connected and responsive to the output of the condition monitoring device causes a particular current to be drawn from the line when the device and signal status are normal than when either is not. An indicator circuit connected into the line and responsive to the current drawn by the device and loading circuit provides a failsafe indication to the operator of the monitored condition and/ or operational status of the system circuitry.