I have a 1997 7500 that has decided to quit running. the symptoms are: generator starts easily, runs, rpms slow and the unit dies. One repair expert says the invertor is bad and will cost 2 grand+ to fix and the invertor fits inside the unit, is 1/3 the size of the unit and needs to come out of the coach. Repair expert #2 says the "processor" or stator/rotor is the issue as the code indicates a category "13" issue. Any insight with this. Sound famaliar and if yes can a normal mechanic like myself replace? Any help would be appreciated!