Onan Generator Service and Parts Manuals Onan Generator Service and Parts Manuals. The following manuals are Onan manuals that are useful for finding and ordering parts for your MEP002A or MEP003A. Note that DJE = the Onan engine used in the MEP002A and DJF = the Onan engine used in the MEP003A. ONAN-SERVICE-MANUAL-YD-GENERATORS-and-CONTROLS-900-0184. Cummins Onan Generator Parts and Manuals - Direct from the Cummins Onan RV Generator Parts & Manuals. When reliability counts, insist on the real thing. From filters to tune-up kits, Genuine Cummins Onan Green Label Parts are made to exact product specifications to maximize the power output and life of your Cummins Onan RV generator.