I would go ahead and jump it. It's going to be
a neg. ground. Chevy came with neg. ground, GMC
with positive. There is no reason why anyone
would want to switch to a positive grd. Also,
if the gen. says 12V and it has a resistor then
its a 12 volt system. Now, having said this,
you don't know if the person who had it wired did it
correctly. So, you still could have some
problems, but getting the juice to it is your
next step and see what goes from there.
