IMO there is no "short"--the pos touching the neg. Fuses are not blowing and wires are not melting. It does seem the pos of one is touching the pos of another. Can't tell about the neg side, but often that is "common" anyway.
The DC fuse panel should say what fuse 1 and 10 are for. What is the individual and total draw of whatever they are for? He says only two lights and the awning are affected. There must be more things on the two circuits?
15a of lights would be only five 3 amp lights, so there must be more light circuits. It seems the awning is tapped into both positives and has a neg somewhere. Or else both positives are touching (wrongly) and the awning is tapped into one of them?
The question seems to be what would happen if the OP turned on all of whatever is really on the 1 and 10 circuits at once. Can anything bad happen other than blowing a 15a fuse (or two)? Can he melt any wires? How?
Is the "short" people are talking about a short that could happen like that screw into the frame going through a pos wire, but there is no short now? If that did happen, isn't that what the 15a fuse is for? Why isn't that enough?
Both positives that are touching are individually fused to 15a and I ASSume are the right gauge wires for 15a circuits. Negs all in common say, but they don't matter AFAIK.
I am not saying it is safe for sure as is, but I have not understood what the problem could be as explained so far :( Thanks.
