A system is provided for implementing a series interlock loop. An example of the interlock system includes a series interlock loop, a data table, and a control module. The series interlock loop has an overall electrical characteristic. The series interlock loop includes first and second safety interlocks electrically coupled in series. Each interlock includes a switch coupled in parallel with an impedance value. The data table is configured to store values corresponding to the impedance values. The control module is communicatively coupled to the data table and configured to receive an indication of the overall electrical characteristic and to compare the overall electrical characteristic to the values in the data table to thereby identify an open one of the first and second safety interlocks.