A high voltage service disconnect assembly for determining an isolation resistance fault of a battery pack, the battery pack having an enclosure, a first battery module, a second battery module, a positive pack voltage terminal, a negative pack voltage terminal, comprising: a housing configured to secure first and second conductive pins (62, 63) thereon; a detection circuit disposed in the housing and electrically coupled to the first and second conductive pins (62, 63), the detection circuit configured to output a first isolation resistance fault signal when a first isolation resistance fault is detected between the negative pack voltage terminal and the enclosure; and a first light emitting device electrically coupled to the detection circuit, the first light emitting device configured to emit light in response to the first isolation resistance fault signal, characterized in that the first conductive pin is configured to be removably electrically coupled to a negative voltage terminal of the first battery module; in that the second conductive pin is configured to be removably electrically coupled to a positive voltage terminal of the second battery module; in that the detection circuit includes a first comparator circuit having a first comparator, a first voltage divider circuit, and a first resistor; the first comparator having a first non-inverting input terminal, a first inverting input terminal, and a first output terminal; in that the first non-inverting input terminal being electrically coupled through the first voltage divider circuit to the negative voltage terminal of the first battery module, the first inverting input terminal being electrically coupled to the enclosure, the first inverting input terminal being further electrically coupled through the first resistor to the negative voltage terminal of the first battery module, the first comparator configured to output the first isolation resistance fault signal on the first output terminal when a first voltage on the first non-inverting input terminal is greater than a second voltage on the first inverting input terminal indicating that the first isolation resistance fault has been detected between the negative pack voltage terminal and the enclosure; and in that the first light emitting device being electrically coupled to the first output terminal. a housing configured to secure first and second conductive pins (62, 63) thereon; a detection circuit disposed in the housing and electrically coupled to the first and second conductive pins (62, 63), the detection circuit configured to output a first isolation resistance fault signal when a first isolation resistance fault is detected between the negative pack voltage terminal and the enclosure; and a first light emitting device electrically coupled to the detection circuit, the first light emitting device configured to emit light in response to the first isolation resistance fault signal, characterized in that the first conductive pin is configured to be removably electrically coupled to a negative voltage terminal of the first battery module; in that the second conductive pin is configured to be removably electrically coupled to a positive voltage terminal of the second battery module; in that the detection circuit includes a first comparator circuit having a first comparator, a first voltage divider circuit, and a first resistor; the first comparator having a first non-inverting input terminal, a first inverting input terminal, and a first output terminal; in that the first non-inverting input terminal being electrically coupled through the first voltage divider circuit to the negative voltage terminal of the first battery module, the first inverting input terminal being electrically coupled to the enclosure, the first inverting input terminal being further electrically coupled through the first resistor to the negative voltage terminal of the first battery module, the first comparator configured to output the first isolation resistance fault signal on the first output terminal when a first voltage on the first non-inverting input terminal is greater than a second voltage on the first inverting input terminal indicating that the first isolation resistance fault has been detected between the negative pack voltage terminal and the enclosure; and in that the first light emitting device being electrically coupled to the first output terminal.