The radio works great without grounding the the neg. side,sound is very clean without the motor running. if you think of a car on rubber tires the antennae is grounded to the frame, mine is too.I think I have a bad ground to the frame, but why would it receive Am and FM clearly, I am going to drill a hole in the windshield frame for a better ground. I got a thread from a guy that said to put a .1mfd. capacitor across the power into the radio , I am going to try that, but first off to the Dentist with a Broken Tooth,there goes
about $1000 for a crown. Won't be buying Cart Parts for awhile.
Dan