I also have a 2011 Fleetwood Storm that has Generator issues. The generator shuts off without warning continuosly. I had it in the shop several times without success. But on a recent trip to Florida the generator shut off every 17 mins without fail. We were frustrated with no AC and 100 degrees outside. A tech in Lake City, Florida (North Florida Welding-highly recommend this shop) tried changing the fuel filter, fuel pump, and fuel line but it did not help. In my case the generator ran fine when sitting still, but died when we drove. The tech from florida called fleetwood repeatedly until he received a reply. A Fleetwood tech returned his call and stated the issue is a design flaw that causes the hot air from the engine to be sucked into the generator causing the unit to overheat. No remedy has been offered for it, so I am stuck with a RV that I can't travel in, and a generator that has overheated numerous times.
Another issue is oil collecting in the air filter. Onan has a kit to repair that under warranty.