Abstract: Circuit arrangement for monitoring an electricity-consuming load fed with direct current one terminal of which is grounded, particularly for monitoring an incandescent of an automotive vehicle, and the circuit arrangement being installable without interfering with the existing network of lines or cutting conductors. Between the switch of the load and the current-consuming device a measurement coil is arranged parallel to a conductor within the magnetic field produced by the flow of electricity through the conductor, the input of the coil being connected to a voltage supply source and its output being connected in a Schmitt trigger circuit with the non-inverting input of a differential amplifier constituted as operational amplifier and the output of the amplifier being fed back via a resistor to the non-inverting input and being connected to a fault indicator.