Hiya DMK, i used to own a Gambler years ago and never had a problem with the electrical. From your description it sounds like you might have a grounding issue. If you have a test light or meter ground it at the cranking battery and test all the fuses. They should light the test light or show full voltage on both sides. If they light on both sides, turn on whatever they go to. If it doesn't work, find the grounding lug and check it and the ground side battery connection. If "nothing" works and there is voltage at the fuses it screams grounding issue to me.