You should have a model 943-B three brush generator. Check to see if the points are closing on the cut-out when you increase the engine speed. If the points are closing and the generator increases voltage when the points close (you can determine this with a volt meter) then the wire could be reversed on the back of the amp meter. If the amp gauge is reading a slight discharge at idle and then more of a discharge when you rev. up the engine, then that is a good indication that the wire is reversed on the back of the amp meter, therefore, the meter is reading in the wrong direction.
If, on the other hand, your generator is not putting out voltage then your generator has a problem. Sometimes when a car sits for awhile the generator will not charge due to a slight film on the commutator. If you have a brush stone you can clean the comm. to see if the generator will charge. If that doesn't work then a generator tear down is probably in order to determine the problem.
