Earlier (non-electronic voltage regulator) Onan generators may lose output if the slip rings oxidize, but won't hurt anything.
Voltage regulator is bad if any pair indicates 'short' or gate by rk kanodia pdf 'open' except for pair 5-10, which should indicate open.
With no load, adjust the speed adjustment nut for 62-63.
Check the wire to the oil pressure sensor - the sensor is located under the cover near the oil filter.One of the features mentioned was "no more start-up failures".Therefor this article is intended for general information only.If you see 12v at P1 pin 5 but not at P4 pin 7, the wiring between them, or the connection at the connectors, is bad.(The following is a compilation of several e-mails between myself and Alan regarding my genset problem.Some of the information below will only make sense and or apply to my specific case so don't let that confuse you if you try and use this information to assess your problem.).If you _don't_ see 12v at J4/P4 pin 7 while cranking, make the same check at P1 ( the connector to the control board ) pin5.We carry the full line of Onan parts.When the start button is pressed it bypasses the oil pressure cut off circuit and the engine will run only if the button is pressed.It may have been knocked off.AJ.5 GenSet (50 Hz) Begin Spec S RV Parts Manual Supplement 924-2000.Skip to main content eBay, enter your search keyword, all Categories, advanced.From this point, turn the adjustment out another /4 turn.We were founded in 1977 by Robert Schwalm to sell and service Generac generator products.It would only be important if you were doing it with the voltage regulator still hooked.It sounds like one of two things - either you are not getting the voltage from the control board to the voltage regulator while cranking ( the field flash voltage that establishes some initial output from the genset or the control board is providing.
Their design is a drop-in replacement.
If there is excess resistance in the field circuit, the regulator has to provide a higher field voltage to get enough current through to provide the necessary field strength.