i agree with jmor.. check the cutout.. it may have finally opened for you :)
If it is the cutout.. gut it and hit radio shack and buy a 25a full wave bridge and wire in one of the segemnts across the arm / bat terminals on the cutout.
for positive ground.. that means gen provides (-).. thus the diode symbols need to be wired a specific way.
one side has a flat line, the other a triangle.
wire the flat line side to arm, and the triangle side to bat.
it's good for 25a which is mor ethan 2x what your genny can make.. and it's got 3 built in spares IF that segment ever gives out.
or you could parallel a set of segments and have 50a capacity.. :), and a spare..