The invention relates to a signal display device for displaying signals on signal paths of a wiring harness, for example, which may be connected to the signal outputs of an electronic apparatus generating/receiving signals, or looped into the signal paths between a signal-generating electronic apparatus and a signal-receiving electronic apparatus. A signal to be displayed each time is measurable from a plurality, preferably all, of the signal paths, and each measured signal is fed to an evaluation unit that, for each measured signal, activates a multicolor display element based on a value of the signal, such that one of several colors may be displayed using the multicolor display element.