Have a 1947 cub with 6 volt positive ground system. Doesn't show charge. I've read posts and watched some video. I did the battery to generator test and got generator to run. I also gounded the field terminal on regulator and got reading on meter of 15 amps when running tractor open so my generator does work. Have a question, my generator has 3 brushes with a 4 post regulator not cut out relay as should be. Could this be my issue? thanks for any advice.