Systems and methods for assembling and wiring photovoltaic arrays are provided. The wiring systems can include retractable wires included in photovoltaic modules that may be extended during installation of photovoltaic modules in the array to connect to wires of adjacent photovoltaic modules, which can retract into a tightened position under the array as the installation is completed. The wires may be made retractable by wire retraction mechanisms mounted to a frame of the photovoltaic module, which maintain a desired tension on the wires of the photovoltaic module. The wire retraction mechanism may include springs that urge components connected to the wire to rotate a particular direction so as to maintain tension on the wire. The wiring systems may also have wire guides to keep the wires accessible for installation and adjustment.