If a google search of a digram was not fruitful; Second thing I would do, is add a fuse block with a 2 or 3 amp fuse to incoming line 86 and land B2 on the load side. Looks like B2 changes primary taps for 6/12v option. Then, W1 white to B1(other side of primary). Then B5 to B3 (neg?) and...