2 wires I believe, will check in the morning. I had the tandem up to 26 mph, didn't think electric bikes could go that fast. It was starting to make a strange noise so I turned it off and pedaled home. It was making a noise that could be described as metal brushing metal. Could it be that it needs to be lubed, I don't see no ports for lube to be added. This is all new to me. I welcome any help, suggestions or random insights.