Just got home from an extended leave of absence and genny gives a RPM sensor fault. Going on 5 weeks ago. Model 5502 installed 2009. 10kW unit on LP. Original battery over 5 years old.

Well did a battery check and my Fluke says 13.5 volts. But then I remember Peddler recommended to check under load by switching to manual with the Fluke clamped.

Sure enough.....13.5 volts went to around 4 to 5 volts under load.

Thanks Peddler for the tip. New battery installed DEKA 526MF (get them at NAPA or Lowes around $75). Genny fired right up.
Seen that several times. Regular replacement is a good thing.