1993 Ford E-Series Van Weird no start - then start

I have to believe the starting of the van after changing the fuse was just coincedence. Fuse size has nothing to do with voltage flow but can cause serious wiring damage or fire if the oversize fused circuit is for some reason is shorted. First thought is, when was the van last tuned up. A simple tune up may be a cheap solution to your starting problems. Also, and importantly, is your description of the engine oil. Oil that looks like a "chocolate malt" is indicitive of coolant leaking into the engine oil. Antifreeze in oil drastically reduces the lubricating ability of oil. If this be the case, the coolant in the oil will act like sandpaper on the engine bearings. I would have this checked out ASAP. Hope this helps.