• Jul 4, 2026 onan generator wiring schematic 4 obfa e startup failures, irregular voltage output, or generator shutdowns. How do I identify the wiring terminals on the Onan 4 OBFA generator? Wiring terminals are labeled according to their function, such as 'R' (regulator), 'S' (stator), or 'G' (ground). Refer to the wiring schematic By Rose Simonis