Onan UF Series Instruction Manual And Parts Catalog page 48

S E R V I C E D I A G N O S I S
17
POSSIBLE CAUSE REMEDY
LOW VOLTAGE OUTPUT OF GENERATOR (Cont.)
Open circuit of shunt field
winding.
Short circuit of windings in
the field or armature.
Manual field rheostat (if used)
adjusted at minimum voltage.
Make proper connections according
to wiring diagram.
Replace defective part.
Adjust manual rheostat.