I have hot tube problems?

i have a sun wave hot tube and the box where the main power switch is, i was wondering if any one knew where i could find a wiring diagram for it, the box is a brett aqualine and the model # is EM-203 and the SN is 87112. My problem is on the relay inside the box there is a black wire that is hooked up to the one side of it and goes to the other side of it and when i turn on the main breaker it trips the breaker but when i unhook the wire it doesnt trip. so im wondering if its hooked up wrong because there is some wires that are just laying there not hooked up to anything so if someone could help me that would be great. thanks.