Just a question or two, here . 6 pin connector ? A 7 pin would be the standard hook up .
By no power do you mean no lights ( turn , brake or park ) & no 12 v feed for trailer battery charge ?
If there is nothing at the connector , I'd be checking further back up the wiring harness, possible the previous owner had a , converter for trailer/toad lights installed ( converts lighting from amber signal lights to standard combo signal brake for the toad/trailer, or vice versa ) and just cut the unit out and took it with him , or it's still there and not working.
For help see
http://www.etrailer.com/faq-wiring.aspx