Sorry for such a lame question, but my power source for my 20-year-old EZ HO track recently died. I bought another one, and now don't remember how to attaché the wires. I have two wires, two places on either side of the retailing track to plug in...do I use both, and piggyback them onto the one set of DC screws on the power source? I've tried every combination I can think of with no luck.