How many circuits would I need as a general rule, to wire up my project? I am not going to use A/C, but I will have a heater, I think. Sometimes need those up here in June! Is there a list somewhere maybe that I can get ideas from. I have a bunch of old wiring including my old Chevy work van. And I have a book with the wiring schematic of that system too. I have seen some systems on ebay that went pretty cheap, like 9 circuit, 12 circuit. Would something like that cover it? I'd probably have to have a RADIO, my Grandson Steve, you know! Thanks a lot in advance. Perley