Speaker wire will work for a SHORT period of time, I say short because the fan draws a LOT of amps and will melt anything smaller than say 12-16 gauage wire in no time at all, but for just testing it you'll be fine. The harness is the big on right on the back of the fan motor. There is only one harness there and it has 3 big wires going into it, on is a ground, next is the low speed power wire, and next to it is the high speed power wire. Connect the female "speaker" connectors on the fan on the ground and high speed power side. (I'll try and take a pic for you if you want) Connect the other bare metal ends of the wire to the battery, hook up the + side first, then touch the other to the ground... it should start immediately. If it does, then you know its not the fan. Its been raining here all damn day too!